Prenatal Hydronephrosis Research Articles

Correlation between renal sonographic measurements and differential renal function obtained from nuclear renography in children with unilateral hydronephrosis

Children with higher grades of hydronephrosis often undergo mercaptoacetyltriglycine nuclear renography scans (MAG3) to assess differential renal function (DRF) and drainage. Although MAG3 helps identify the potential need for pyeloplasty, its use incurs increased costs, radiation exposure, and stress for children and families. Several studies demonstrate pyramidal thickness (PT)≤3mm as a reliable predictive risk factor for pyeloplasty in children with a history of prenatal hydronephrosis. Our hypothesis was that renal sonographic measurements including PT and parenchymal thickness (ParT) correlate with DRF in children with high-grade unilateral hydronephrosis and may be used to better select the need and frequency of MAG3 scans in children at increased risk for diminished relative renal function. The objective of this project was to determine the correlation between sonographic renal measurements and DRF in patients with unilateral hydronephrosis, we assessed: 1) the correlation between PT, ParT, and the ratio of PT/ParT in hydronephrotic kidneys to DRF, 2) the correlation between the ratio of hydronephrotic PT/contralateral non-hydronephrotic PT and DRF, 3) the correlation between the ratio of hydronephrotic ParT/contralateral non-hydronephrotic ParT and DRF, and 4) the correlation between the ratio of (hydronephrotic PT/ParT)/(contralateral non-hydronephrotic PT/ParT) and DRF. We retrospectively reviewed 71 children with grades 3 or 4 unilateral hydronephrosis. Most patients presented with a history of prenatally detected hydronephrosis at median age (IQR) of 112 days (43-274). Measurements of PT and ParT were completed on 98 renal ultrasounds and DRF was collected from corresponding MAG3 scans. Threshold values were identified visually through scatterplots. Spearman's correlation coefficient and Fisher's p-values were calculated. Ratios of PT and ParT in hydronephrotic kidneys to contralateral non-hydronephrotic kidneys were positively correlated with DRF. Ratios of hydronephrotic PT/non-hydronephrotic PT>0.8 and hydronephrotic ParT/non-hydronephrotic ParT >0.7 occurred more frequently in patients with a DRF >40% (p=0.11 and p=0.001, respectively). A PT>3mm and ParT >5mm occurred significantly more frequently in patients with a DRF >40% (p=0.008 and p=0.006, respectively). Renal sonographic measurements including threshold values of PT>3mm, ParT > 5mm, ratio of hydronephrotic PT/contralateral non-hydronephrotic PT (>0.8), and ratio of hydronephrotic ParT/contralateral non-hydronephrotic ParT (>0.7) are good predictors of DRF >40% in unilateral high-grade hydronephrosis. These identified threshold values have potential utility in determining the need for nuclear renal scans in children with high-grade hydronephrosis.

Open distal ureteroureterostomy for non-refluxing duplicated collecting system in children: Multicentric study and mid-term outcomes

When indicated, ureteroceles and ectopic ureters in duplicated collecting systems can be managed via upper or lower urinary tract surgical approaches, or a combination of both. Open ureteroureterostomy (UU) has been described to address these conditions in the absence of lower pole (LP) vesicoureteral reflux (VUR). We report outcomes from multiple centers worldwide with mid-term follow-up. Our study consists of a retrospective review of records and imaging of children who underwent open distal UU via inguinal incision for duplicated collecting system without lower pole VUR in institutions from North America, South America, and the Caribbean. Descriptive statistics and univariate analysis were utilized. The records of 127 patients who underwent open distal UU for double collecting system between 2009 and 2022 were reviewed. Of those, 65% were female (n=82), with a mean age at operation of 18 months (range 3-180). Main presentation at surgery included prenatal hydronephrosis (64%, n=81), followed by febrile urinary tract infections (28%, n=36), and urinary incontinence or other (8%, n=10). The patients with antenatal or incidental diagnosis of hydronephrosis were classified as preoperative Society for Fetal Urology (SFU) grade 3 (n=64) and 4 (n=54) (96%). Those who were classified with SFU grade 0-2 (4%) had symptomatic clinical presentations including febrile urinary tract infections (UTIs) (n=3), urinary incontinence (n=3), and a 12-year-old patient with recurrent abdominal pain (n=1). Mean operative time from skin incision to skin closure was 86min (range 45-240). Mean hospital stay was estimated at 1.1 days (range 0.5-4). In our cohort of 127 patients, 3 (2%) developed Clavien-Dindo grade I (2 with ureteral stent displacement and 1 with a urine leak/managed conservatively), 6 (5%) with grade II (3 febrile and 3 non-febrile UTIs managed with oral antibiotics), and 2 (2%) with grade IIIb complications (urine leaks requiring surgical management), which were appropriately treated. None presented grade IV or V complications. A double J stent was used in 56 patients (44%), and a Penrose drain was left in 10 (8%). A total of 125 children (98%, n=125/127) showed sonographic improvement of hydronephrosis, or resolution of symptoms with stable ultrasound findings. Successful outcome was similar for both ureterocele and ectopic ureter subgroups: 49/49 patients with ureterocele showed 100% improvement, 76/78 children with ectopic ureter showed improvement in 97% of the cases. On univariate analysis, outcomes were similar regardless of the use of ureteral stents (p=0.11). Mean follow-up was 28.2 months (range 12-85). Open distal UU is a good alternative for the definitive surgical management of ectopic ureters and ureteroceles without LP VUR. This multicentric and mid-term follow-up study demonstrates that open distal UU offers high success rates, low morbidity, short operative times and hospital stays, and satisfactory aesthetic outcomes. Additionally, the surgery is performed extra-peritoneally and may not require the use of stents or drains, depending on surgeon preference. Further investigations are being conducted to determine the role of UU in the settings of double collecting systems associated with ipsilateral LP VUR.

Automated grading of prenatal hydronephrosis severity from segmented kidney ultrasounds using deep learning

Background and motivationsAntenatal or prenatal hydronephrosis (AHN) is a common kidney complication in unborn children. While AHN is generally benign and resolves over time, this condition can inflict serious kidney damage or even organ failure due to excessive waste accumulation in severe cases. Regardless of severity, AHN must be clinically monitored for resolution, with treatment plans and medications being revised according to updated prognoses. Kidney ultrasound images are one of the most common methods of monitoring AHN, but grading of this condition is highly subjective and clinicians may select inappropriate therapies or surgical interventions as a result. New approaches are required to differentiate subjects who can be managed without surgical intervention from those who require life-saving operations. MethodsAn end-to-end deep machine learning framework was developed to sequentially detect ultrasound regions of interest, segment kidneys from US images, and classify AHN severity. We propose the novel Kidney Ultrasound Segmentation Network (KUSNet) for kidney segmentation from ultrasound images, and the Prenatal Hydronephrosis Classification Network (PHCNet) for hydronephrosis severity stratification according to the Society of Fetal Urology (SFU) standards. The ground truth kidney masks were generated by two radiologists with more than five years of working experience while the SFU-based annotations for the AHN severity were done by two senior radiologists and three senior urologists with more than ten years of domain expertise. At each stage, the performance of the proposed models was assessed both quantitatively and qualitatively against state-of-the-art networks in the respective fields. ResultsThe proposed KUSNet for ultrasound kidney segmentation achieved 97.6% accuracy, 97.4% precision, 97.6% recall or sensitivity, 97.5% F1-score, 95.5% IoU or Jaccard score, and 92.1% Dice score, beating several state-of-the-arts. On the other hand, the novel PHCNet reached 93.9% accuracy, 93.7% precision, 93.9% recall, 93.8% specificity, and 89.0% F1-score subject-wise when performing multiclass stratification of AHN severity on segmented kidney regions. ConclusionArtificial intelligence-based tools can reliably classify AHN severity to reduce inter- and intra-observer bias, thereby aiding clinicians in the rapid selection of appropriate treatments and surgeries. Moreover, segmenting kidney regions beforehand significantly boosts AHN severity classification performance.

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

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

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

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. From our prospectively collected prenatal hydronephrosis (HN) database (0-24months, 2008-2017), selecting those with NRPM (n=92). We excluded patients who underwent surgery (n=20), children with <6months 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) <10mm, and ureteric dilatation <5mm. Descriptive statistics and Kaplan-Meier curves were created for time-to-resolution analyses. Of 66 patients and 198 ureteral segments, median age at presentation was 2months (0-12), 83% were male (33% circumcised). Mean APD at baseline was 11±4mm, 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). Our data suggest that spontaneous resolution of NRPM follows a proximal to distal progression. Distal ureteric dilatation takes up to 10months longer to resolve compared to that of proximal and mid-ureteric segments, as well as that of the renal pelvis.

Obstrucción congénita de la unión ureteropiélica. Estudio de casos en un centro de segundo nivel

Objective: To evaluate the incidence, clinical characteristics, diagnosis, and treatment of congenital ureteropelvic junction obstruction in pediatric patients (CUPBO) at the Hospital Infantil de Morelia. Material and methods: This was a retrospective, observational, descriptive, and cross-sectional study of pediatric patients diagnosed with CUPBO and treated in the urology service of a second-level care medical center from January 2018 to December 2021. Results: We reviewed 53 patients with prenatal hydronephrosis who underwent postnatal follow-up, of whom only 6 patients diagnosed with congenital ureteropelvic junction obstruction (CUPBO) were identified prenatally. Seven patients were diagnosed with hydronephrosis postnatally and subsequently diagnosed with CUPBO, resulting in a total sample of 13 diagnosed patients. The incidence of CUPBO was 3.4 patients per 100 first visits to the Pediatric Urology Service. Of the cases, 92.31% were male, and the most frequent clinical manifestations were skin infections and localized pain. Surgery was performed in all cases, with Anderson-Hynes pyeloplasty being the most frequent procedure. Complications included urinary tract infections, wound infections, and fistula, but most patients had satisfactory results with a reduction of hydronephrosis after surgery. Findings or conclusions: Our study found a low rate of early detection of CUPBO in patients with prenatal hydronephrosis follow-up. We recommend an intentional search for urologic alterations in structural ultrasound scans of prenatal control. We emphasize the importance of an accurate diagnosis and timely treatment of CUPBO to prevent renal complications.

Clinical characteristics of patients with prenatal hydronephrosis in early postnatal period: a single center retrospective study

BackgroundThe study aims to investigate the clinical characteristics of early postnatal period in children with prenatal hydronephrosis (HN) in our single center for 8 years.Study designThe clinical data of 1137 children with prenatal HN from 2012 to 2020 were retrospectively analyzed in our center. Variables of our study mainly included different malformations and urinary tract dilation (UTD) classification, and main outcomes were recurrent hospitalization, urinary tract infection (UTI), jaundice, and surgery.ResultsAmong the 1137 children with prenatal HN in our center, 188 cases (16.5%) were followed-up in early postnatal period, and 110 cases (58.5%) were found malformations. The incidence of recurrent hospitalization (29.8%) and UTI (72.5%) were higher in malformation, but the incidence of jaundice (46.2%) was higher in non-malformation(P < 0.001). Furthermore, UTI and jaundice were higher in vesicoureteral reflux (VUR) than those in uretero-pelvic junction obstruction (UPJO) (P < 0.05). Meanwhile, Children with UTD P2 and UTD P3 were prone to recurrent UTI, but UTD P0 was prone to jaundice (P < 0.001). In addition, 30 cases (16.0%) of surgery were all with malformations, and the surgical rates of UTD P2 and UTD P3 were higher than those of UTD P0 and UTD P1 (P < 0.001). Lastly, we concluded that the first follow-up should be less than 7 days, the first assessment should be 2 months, and the follow up should be at least once every 3 months.ConclusionChildren with prenatal HN have been found many malformations in early postnatal period, and with high-grade UTD were more prone to recurrent UTI, even to surgery. So, prenatal HN with malformations and high-grade UTD should be followed up in early postnatal period regularly.

Association of the Hydronephrosis Severity Score With Likelihood of Pyeloplasty: A Large Prospective Database Analysis

To apply and reproduce this scoring system in our prenatal hydronephrosis population with ureteropelvic junction obstruction (UPJO)-like hydronephrosis (HN), specifically looking at determining better HHS cutoffs that would allow for stratification into three risk categories: spontaneous HN resolution, observation, and surgery. A prospectively collected prenatal hydronephrosis database was reviewed to extract UPJO-like HN patients. Children with vesicoureteral reflux, primary megaureter, bilateral HN, and other associated anomalies were excluded. Only patients who had an ultrasound and mercaptoacetyltriglycine renal scan at a minimum of 2-time points were included. Hydronephrosis Severity Score was calculated at the initial, interim, and last follow-up clinic visits. Scores were analyzed regarding its usefulness to determine which patients would have been more likely to undergo pyeloplasty. Of 167 patients, 131 (78%) were male, 119 (71%) had left UPJO-like, and 113 (67%) had a pyeloplasty. The median age at baseline was 2months (interquartile range 1-4). According to initial (first clinic visit) Hydronephrosis Severity Score, 5/36 (14%) patients with a 0-4 score, 93/116 (80%) with a 5-8 score, and 15/15 (100%) with a 9-12 score underwent pyeloplasty, respectively (P<.01). The proposed HHS system for UPJO-like HN patients is reproducible, however, cut-off values need to be reassessed to accurately reflect true risk categories, as the purpose of this system is to differentiate those who have HN severe enough to require intervention from those who can be managed nonsurgically. Changing risk groups to mild (0-3), moderate (4-6), and severe (7-12) allowed for better discrimination between patients who underwent surgical intervention from those who did not in our dataset.

Multicenter comparative study of open, laparoscopic, and robotic pyeloplasty in the pediatric population for the treatment of ureteropelvic junction obstruction (UPJO).

Dismembered open pyeloplasty described by Anderson and Hynes is the "gold standard" for the treatment of ureteropelvic junction obstruction. The aim of our study was to compare the results of open (OP) vs laparoscopic (LP) vs robotic (RALP) pyeloplasty. A multicenter prospective review was conducted of pyeloplasty surgeries performed at five high-volume centers between 2014 and 2018. Demographic data, history of prenatal hydronephrosis, access type, MAG3 renogram and differential renal function, surgery time, length of hospital stay, and complication rate (Clavien-Dindo) were recorded. Access type was compared using the Kruskal-Wallis, Chi-square, or Fisher's exact tests. A total of 322 patients were included: 62 OP, 86 LP, and 174 RALP. The mean age was 8.13 (r: 1-16) years, with a statistically significant lower age (mean 5 years) in OP (p < 0.001). There were no significant differences in the distribution of the side affected. Operative time was 110.5 min for OP, 140 min for LP, and 179 min for RALP (p < 0.0001). Hospital stay was significantly shorter in the RALP group than in the other groups (p < 0.0001). There were no differences in postoperative complications and reoperations between the three groups. Minimally invasive surgery for the management of UPJO in children is gaining more acceptance, even in patients younger than 1-year-old. Operative time continues to be significantly shorter in OP than in LP and RALP. Hospital stay was shorter in RALP compared to the other techniques. No differences were found in complication rates, type of complications, and reoperation rate.

Early detection of ureteropelvic junction obstruction in neonates with prenatal diagnosis of renal pelvis dilatation using 1H NMR urinary metabolomics

Renal pelvis dilatation (RPD) is diagnosed in utero on prenatal ultrasonography (US) and can resolve spontaneously. However, isolated RPD can also reflect ureteropelvic junction obstruction (UPJO), which requires surgical treatment to prevent progressive renal deterioration. The diagnosis of UPJO can only be confirmed after birth with repeat US and renal isotope studies. 1H Nuclear Magnetic Resonance spectroscopy (NMR) was performed on urine of newborns with prenatally diagnosed unilateral RPD and healthy controls to identify specific urinary biomarkers for UPJO. The original combination of EigenMS normalization and sparse partial-least-squares discriminant analysis improved selectivity and sensitivity. In total, 140 urine samples from newborns were processed and 100 metabolites were identified. Correlation network identified discriminant metabolites in lower concentrations in UPJO patients. Two main metabolic pathways appeared to be impaired in patients with UPJO i.e. amino acid and betaine metabolism. In this prospective study, metabolic profiling of urine samples by NMR clearly distinguishes patients who required surgery for UPJO from patients with transient dilatations and controls. This study will pave the way for the use of metabolomics for the diagnosis of prenatal hydronephrosis in clinical routine.

Application of the postnatal urinary tract dilation classification system to predict the need for surgical intervention among neonates and young infants.

The aim of this study was to validate the postnatal urinary tract dilation (UTD) classification system by correlating it with the need for surgical intervention. Young infants who underwent ultrasound (US) examinations for prenatal hydronephrosis were retrospectively identified. The kidney units (KUs; right, left, or bilateral) were graded from UTD P0 (very low risk) to P3 (high risk) based on seven US criteria from the UTD system. Surgery-free survival curves were constructed using the Kaplan-Meier method. Univariable and multivariable Cox proportional-hazards regression analysis clustered by patients was performed. Interobserver agreement was analyzed using the weighted kappa coefficient. In total, 504 KUs from 336 patients (mean age, 18.3±15.9 days; range, 1 to 94 days; males, n=276) were included, with a median follow-up of 24.2 months. Fifty-eight KUs underwent surgical intervention. Significant differences were observed among the Kaplan-Meier curves stratified into UTD groups (P<0.001). The presence of anterior-posterior renal pelvic diameter ≥15 mm (hazard ratio [HR], 8.602; 95% confidence interval [CI], 1.558 to 43.065), peripheral calyceal dilation (HR, 8.190; 95% CI, 1.558 to 43.065), ureteral dilation (HR, 2.619; 95% CI, 1.274 to 5.380), parenchymal thickness abnormality (HR, 3.371; 95% CI, 1.574 to 7.223), bladder abnormality (HR, 12.209; 95% CI, 3.616 to 41.225) were significantly associated with the occurrence of surgery. The interobserver agreement was moderate to almost perfect agreement for US features (κ=0.564-0.898) and substantial for final UTD grades (κ=0.716). The UTD classification system is reliable and appropriately stratifies the risk of surgical intervention.

Upper pole pathologies in duplex kidneys: an analysis of predictive factors for surgery and urinary tract infections from the Mid-Atlantic Pediatric Academic Consortium

While there is significant data on the natural history and outcomes for prenatal hydronephrosis in simplex kidneys, duplex kidneys tend to be less studied. Management can be quite variable based on provider preference. We aimed to describe practice patterns from several tertiary academic institutions, identify clinical predictors for surgical intervention and urinary tract infection (UTI) for upper pole pathology, and demonstrate the natural history of lower pole vesicoureteral reflux (VUR). We conducted a retrospective review of patients from 4 Mid-Atlantic institutions between 2015 and 2020. Inclusion criteria included patients with a duplex kidney with upper pole pathology and/or lower pole VUR. The primary outcome was predictive factors for surgical intervention and UTI. The secondary outcome was to assess the natural history of lower pole VUR including resolution rates by grade. Linear regression identified clinical predictors for UTI events. Multivariate logistic regression identified predictors of surgical intervention, UTI, and lower pole VUR resolution. Descriptive statistics and regression modeling analyses were performed using SAS. Two hundred forty-two patients were included with a total of 271 duplex renal units. Hydronephrosis grade (both SFU and UTD grading) and number of prior UTI events were statistically significant predictors for surgical intervention (p=0.03/0.001 and p=0.002 respectively). Ectopic ureter (p=0.004), ureterocele (p=0.02), and obstruction (p=0.04) were the only pathologies predictive for surgery. Male gender and circumcision were significantly associated with decreased UTI risk (p=0.03 and p=0.01). On linear regression modeling, antibiotic prophylaxis after the first year of life was associated with decreased risk of further UTI events (p=0.03); however, antibiotic prophylaxis within the first year of life did not decrease UTI risk (p=0.14). For VUR outcomes, 65.0% of grades 1-3 VUR and 52.2% of grades 4-5 had resolution/improvement at mean time of 2.1 years. There were no predictive factors for resolution/improvement of VUR. Hydronephrosis grade and UTI events were significant predictors for surgical intervention for upper pole pathology. Pathologies that were predictive for surgery included ectopic ureter, ureterocele and obstruction. Male gender, circumcision and antibiotic prophylaxis after the first year of life were associated with a decreased UTI risk. Roughly 58% of lower pole VUR spontaneously improved/resolved. Identification of these risk factors aids in standardization of care practices to reduce long-term UTI risk and inform counseling with families about possible need for surgical intervention and expectations for long term outcomes.

Continuous antibiotic prophylaxis in isolated prenatal hydronephrosis

Prenatal hydronephrosis (PNH) is one of the most common congenital anomalies and can increase the risk of developing a urinary tract infection (UTI) in the first two years of life. Continuous antibiotic prophylaxis (CAP) has been recommended empirically to prevent UTI in children with PNH, but its use has been controversial. We describe the incidence of UTI in children with isolated PNH of the renal pelvis without ureteral dilation. Our objective was to compare patients receiving and not receiving CAP and determine whether CAP is beneficial at preventing UTI in children with isolated PNH. Children with confirmed PNH were enrolled between 2008 and 2020 into the Society for Fetal Urology Hydronephrosis Registry. Children with isolated dilation of the renal pelvis without ureteral or bladder abnormality were included. The primary outcome was development of a UTI, comparing patients who were prescribed and not prescribed CAP. In this cohort of 801 children, 76% were male, and 35% had high grade hydronephrosis (SFU grades 3-4). CAP was prescribed in 34% of children. The UTI rate among all children with isolated PNH was 4.2%. Independent predictors of UTI were female sex (HR=13, 95% CI: 3.8-40, p=0.0001), intact prepuce (HR=5.1, 95% CI: 1.4-18, p=0.01) and high grade hydronephrosis (HR=2.0, 95% CI: 0.99-4.0, p=0.05; Table) on multivariable analysis. For patients on CAP, the UTI rate was 4.0% compared to 4.3% without CAP (p=0.76). The risk of UTI during follow-up was not significantly different between patients who received CAP and patients who were not exposed to CAP; adjusting for sex, circumcision status and hydronephrosis grade (HR=0.72, 95% CI: 0.34-1.5, p=0.38). In sub-group analysis of patients at higher risk of UTI (uncircumcised males, females and high grade hydronephrosis), CAP use was not associated with a statistically significant reduction in UTI. The overall UTI rate in children with isolated PNH is very low at 4.2%. In the overall population of patients with isolated PNH, CAP was not associated with reduction in UTI risk, although the limitations in our study make characterizing CAP effectiveness difficult. Clinicians should consider risk factors prior to placing all patients with isolated PNH on CAP.

Prenatal hydronephrosis: Bridging pre- and postnatal management.

Urinary tract dilation (UTD), including hydronephrosis (HN) is the most common prenatally detected anomaly and affects up to 1%-2% of pregnancies. Postnatally, it resolves without surgical intervention in approximately 75%-80% of children, however this may take several years to occur, necessitating repeated clinic visits and additional invasive testing for many. For the remainder, a surgical intervention will be offered to relieve obstruction or to correct vesicoureteral reflux. During the monitoring period, many of these infants will be offered continuous antibiotic prophylaxis for the prevention of urinary tract infections, however this remains a controversial topic among pediatric urologists and nephrologists. Herein, we present an up-to-date review of the early management of prenatally detected UTD including timing of postnatal imaging, the use of antibiotics, when circumcision may be beneficial and long term outcomes of the most common HN etiologies. We also propose a decision making tool to help guide the care of infants with UTD.

Manejo não cirúrgico da obstrução da junção vesicoureteral: um relato de caso

Objective:To report the case of a pediatric patient with bilateral hydronephrosis due to vesicoureteral junction obstruction (VUJO) that was treated non-surgically and to discuss the approach of this anomaly.Case Description:A 25-month-old boy was referred without complaints for consultation due to prenatal ultrasound showing kidneys with cysts. He was under antibiotic prophylaxis. No family history of kidney disease and/or inherited disorders was reported. Renal ultrasound (RUS) at 2 days of life showed bilateral hydronephrosis, thus ruling out the possibility of kidney cystic disease. Dynamic renal scintigraphy (DTPA) showed marked retention of the marker in the pyelocaliceal system bilaterally, with little response to diuretic drug. He was maintained under antibiotic prophylaxis, when a new RUS showed bilateral ureteral dilatation, abrupt stenosis in the ureterovesical transition region (0.2 cm caliber), moderate bilateral hydronephrosis, and slight renal cortical thickness, confirming the diagnosis of VUJO. At 2 years and 10 months of age, DTPA showed hydronephrosis and ureteral stasis in both kidneys secondary to stenosis at the vesicoureteral junction (VUJ) level, with preservation of kidney function and slow degree of emptying. We opted for a non-surgical approach. RUS at 10 years of age showed significant improvement of all parameters, with ureteral transverse diameter of 9 mm, preserved VUJ, and age-appropriate bilateral kidney development.Comments:VUJO is a major cause of prenatal hydronephrosis and can trigger a deterioration of kidney function. Its treatment is still controversial but should take into account the importance of clinical follow-up and serial imaging evaluation.

Congenital midureteral stenosis in children: a 13-year retrospective study based on data from a large pediatric medical center

BackgroundMidureteral stenosis is very rare in children and can cause congenital hydronephrosis. We report our experience treating children with congenital midureteral stenosis at our center, focusing on the differences in preoperative diagnosis and treatment compared with other congenital obstructive uropathies.MethodsWe retrospectively reviewed the medical records of 26 children diagnosed with congenital midureteral stenosis at our center between January 2007 and December 2020, such as preoperative examination methods, intraoperative conditions, and postoperative follow-up results.ResultsOf the 1625 children treated surgically for ureteral narrowing, only 26 (1.6%) were diagnosed with midureteral stenosis, including 15 infants and 11 children. Eighteen (69.2%) were boys, 13 (50%) were affected on the left side, and 23 (88.5%) had isolated ureteral stenosis. Overall, 13 (50%) of the children presented with prenatal hydronephrosis, and 13 (50%) presented with abdominal pain or a mass. All the children had undergone urinary ultrasound and intravenous urography preoperatively; the diagnostic rate of ultrasound was 92.3%. Only 7 (26.9%) children had undergone pyelography. All the children had undergone surgery. The ureteral stenotic segment was less than 1 cm long in 25 (96.2)% of the children. The mean follow-up duration was 22 months (range: 6–50 months). One child developed anastomotic strictures. Urinary tract obstruction was relieved in the other children without long-term complications.ConclusionsCongenital midureteral stenosis is rare, accounting for 1.6% of all ureteral obstructions, and its diagnosis is crucial. Urinary ultrasound has a high diagnostic rate and should be the first choice for midureteral stenosis. Retrograde pyelography can be used when the diagnosis is difficult, but routine retrograde pyelography is not recommended. Congenital ureteral stenosis has a relatively short lesion range, largely within 1 cm. The treatment is mainly resection of the stenotic segment and end-to-end ureteral anastomosis, with a good prognosis.

Risk of urinary tract infection in patients with hydroureter: An analysis from the Society of Fetal Urology Prenatal Hydronephrosis Registry

Prenatal hydronephrosis is one of the most common anomalies detected on prenatal ultrasonography. Patients with prenatal hydronephrosis and ureteral dilation are at increased risk of urinary tract infection (UTI) and continuous antibiotic prophylaxis (CAP) is recommended. However, current guidelines do not define the minimum ureteral diameter that would be considered a dilated ureter in these patients. We evaluate the definition of clinically relevant hydroureter, its association with UTI, and the impact of CAP. Patients with prenatal hydronephrosis from seven centers were enrolled into the Society for Fetal Urology Prenatal Hydronephrosis Registry from 2008 to 2020. Patients with ureteral measurement on ultrasound were included. Patients with ureterocele, ectopic ureter, neurogenic bladder, posterior urethral valves, horseshoe or solitary kidney, known ureteropelvic junction obstruction, or follow-up less than one month were excluded. Primary outcome was UTI. Analyses were performed using Cox regression. Of the 1406 patients enrolled in the registry, 237 were included. Seventy-six percent were male, ureteral diameter ranged from 1 to 34mm, and median follow-up was 2.2 years. Patients with ureters 7mm or greater had nearly three times the risk of UTI adjusting for sex, circumcision status, antibiotic prophylaxis and hydronephrosis grade (HR=2.7, 95% CI: 1.1-6.5, p=0.03; Figure). In patients who underwent voiding cystourethrogram (VCUG; 200/237), ureteral dilation of 7mm or more identified patients at increased UTI risk controlling for sex, circumcision status, vesicoureteral reflux and hydronephrosis grade (HR=2.3, 95% CI: 0.97-5.6, p=0.06). CAP was significantly protective against UTI (HR=0.50 (95% CI: 0.28-0.87), p=0.01). Among patients who underwent VCUG and did not have vesicoureteral reflux, ureteral dilation 7mm or greater corresponded with higher UTI risk compared to ureteral diameter less than 7mm on multivariable analysis (HR=4.6, 95% CI: 1.1-19.5, p=0.04). This is the first prospectively collected, multicenter study to demonstrate that hydroureter 7mm or greater identifies a high-risk group for UTI who benefit from antibiotic prophylaxis. In contrast, patients with prenatal hydronephrosis and non-refluxing hydroureter less than 7mm may be managed more conservatively.

PD15-10 PRENATAL HYDRONEPHROSIS WITH URETERAL DILATION SEVEN MILLIMETERS OR GREATER IDENTIFIES PATIENTS AT INCREASED RISK OF URINARY TRACT INFECTION

You have accessJournal of UrologyPediatric Urology I (PD15)1 Sep 2021PD15-10 PRENATAL HYDRONEPHROSIS WITH URETERAL DILATION SEVEN MILLIMETERS OR GREATER IDENTIFIES PATIENTS AT INCREASED RISK OF URINARY TRACT INFECTION Sarah Holzman, Rebecca Zee, Luis Braga, C. D. Anthony Herndon, Carol Davis-Dao, Nora Kern, Joshua Chamberlin, Melissa McGrath, Kai-wen Chuang, Heidi Stephany, Elias Wehbi, Anne Dudley, Valre Welch, Gina Lockwood, Jennika Finup, and Antoine Khoury Sarah HolzmanSarah Holzman More articles by this author , Rebecca ZeeRebecca Zee More articles by this author , Luis BragaLuis Braga More articles by this author , C. D. Anthony HerndonC. D. Anthony Herndon More articles by this author , Carol Davis-DaoCarol Davis-Dao More articles by this author , Nora KernNora Kern More articles by this author , Joshua ChamberlinJoshua Chamberlin More articles by this author , Melissa McGrathMelissa McGrath More articles by this author , Kai-wen ChuangKai-wen Chuang More articles by this author , Heidi StephanyHeidi Stephany More articles by this author , Elias WehbiElias Wehbi More articles by this author , Anne DudleyAnne Dudley More articles by this author , Valre WelchValre Welch More articles by this author , Gina LockwoodGina Lockwood More articles by this author , Jennika FinupJennika Finup More articles by this author , and Antoine KhouryAntoine Khoury More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001997.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Prenatal hydronephrosis with concomitant hydroureter is an established risk factor for urinary tract infection (UTI); however, the minimum ureteral diameter for hydroureter is not well defined. We evaluated the definition of clinically significant hydroureter, its association with UTI and whether continuous antibiotic prophylaxis (CAP) impacted UTI risk. METHODS: Patients with prenatal hydronephrosis from seven centers were enrolled into the Society for Fetal Urology Hydronephrosis Registry from 2008-2020. Patients with ureteral measurement on ultrasound were included. Patients with ureterocele, ectopic ureter, neurogenic bladder, posterior urethral valves, horseshoe or solitary kidney, known ureteropelvic junction obstruction, or follow-up <1 month were excluded. Primary outcome was UTI. Analyses were performed using Cox regression. RESULTS: Of 1406 enrollees, 237 met inclusion criteria. Hydroureter of 7 mm was a significant threshold to differentiate patients at higher UTI risk. Patients with ureters ≥7 mm had almost three times the risk of UTI adjusting for sex, circumcision, CAP, and hydronephrosis grade (HR=2.7, 95% CI:1.1-6.5, p=0.03). In patients without vesicoureteral reflux (VUR), ureteral dilation ≥7 mm corresponded with higher UTI risk compared to ureteral diameter <7 mm on multivariable analysis (HR=4.6, 95% CI: 1.1-19.5, p=0.04; Figure 1). Conversely, in patients with VUR, ureteral diameter ≥7 mm did not impact UTI risk (HR=1.1, 95% CI:0.31-3.6, p =0.93). CAP was significantly protective against UTI for patients with hydroureter (HR=0.50, 95% CI: 0.28-0.87, p=0.01). CONCLUSIONS: This is the first prospectively collected, multicenter study to show that prenatal hydronephrosis with hydroureter ≥7 mm identifies a high UTI risk group who would benefit from antibiotic prophylaxis. In contrast, patients with prenatal hydronephrosis and non-refluxing hydroureter <7 mm may be managed more conservatively. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e276-e276 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sarah Holzman More articles by this author Rebecca Zee More articles by this author Luis Braga More articles by this author C. D. Anthony Herndon More articles by this author Carol Davis-Dao More articles by this author Nora Kern More articles by this author Joshua Chamberlin More articles by this author Melissa McGrath More articles by this author Kai-wen Chuang More articles by this author Heidi Stephany More articles by this author Elias Wehbi More articles by this author Anne Dudley More articles by this author Valre Welch More articles by this author Gina Lockwood More articles by this author Jennika Finup More articles by this author Antoine Khoury More articles by this author Expand All Advertisement Loading ...

MP44-06 ULTRASOUND CONTRAST-ENHANCED VOIDING CYSTOURETHROGRAM FOR DIAGNOSIS OF VESICOURETERAL REFLUX: SINGLE-INSTITUTION EXPERIENCE

You have accessJournal of UrologyPediatric Urology II (MP44)1 Sep 2021MP44-06 ULTRASOUND CONTRAST-ENHANCED VOIDING CYSTOURETHROGRAM FOR DIAGNOSIS OF VESICOURETERAL REFLUX: SINGLE-INSTITUTION EXPERIENCE Thomas Williams, Lane Palmer, John Amodio, and Jeffrey Palmer Thomas WilliamsThomas Williams More articles by this author , Lane PalmerLane Palmer More articles by this author , John AmodioJohn Amodio More articles by this author , and Jeffrey PalmerJeffrey Palmer More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002065.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The current standard diagnostic method for vesicoureteral reflux (VUR) is fluoroscopic voiding cystography (VCUG). However, exposure to this inherent ionizing radiation may increase the risk of developing a malignancy in this vulnerable population. The development of stable and reproducible intravesical ultrasound contrast agents and techniques offer an opportunity to diagnose VUR without radiation exposure. This study highlights a large volume, single-institution’s experience of ultrasound contrast-enhanced VCUG and reported outcomes. METHODS: Retrospective chart review for 143 pediatric patients who underwent ultrasound contrast-enhanced VCUG at a single children’s hospital between 2018 and 2020. Technique involved several voiding and filling cycles with 1cc of Lumason® microbubbles, mixed with normal saline, and instilled via catheter gravity drip. Primary outcomes measured grade of VUR (International Reflux Grading System) as interpreted by a trained pediatric radiologist. Additionally, related anatomical findings, indications for exam, and clinical outcomes were reported. RESULTS: Mean age ranged from newborn to 14 years of age (18.7 ± 33.6 months, mean ± SD). The predominant indication for examination was prenatal hydronephrosis, 85 patients (59.4%) followed by history of urinary tract infection, 46 patients (32.2%). Overall, VUR was detected in 41 patients (28.7%) with total of 58 renal units. VUR was more commonly noted on the left side - 31 renal units (53.4%) but without difference in reflux grade (3.1 vs 3.0). Reflux grade breakdown was Grade I (0), Grade II (19), Grade III (23), Grade IV (9), and Grade V (7). There were no complications. CONCLUSIONS: Ultrasound contrast-enhanced VCUG is a safe and efficient alternative to the diagnosis of VUR without exposure to ionizing radiation. Future studies should continue to explore exam reproducibility and comparison between that of fluoroscopic VCUG. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e794-e795 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Thomas Williams More articles by this author Lane Palmer More articles by this author John Amodio More articles by this author Jeffrey Palmer More articles by this author Expand All Advertisement Loading ...

Predictive accuracy of prenatal ultrasound findings for lower urinary tract obstruction: A systematic review and Bayesian meta-analysis.

Lower urinary tract obstruction (LUTO) is a rare but critical fetal diagnosis. Different ultrasound markers have been reported with varying sensitivity and specificity. The objective of this systematic review and meta-analysis was to identify the diagnostic accuracy of ultrasound markers for LUTO. We performed a systematic literature review of studies reporting on fetuses with hydronephrosis or a prenatally suspected and/or postnatally confirmed diagnosis of LUTO. Bayesian bivariate random effects meta-analytic models were fitted, and we calculated posterior means and 95% credible intervals for the pooled diagnostic odds ratio (DOR). A total of 36,189 studies were identified; 636 studies were available for full text review and a total of 42 studies were included in the Bayesian meta-analysis. Among the ultrasound signs assessed, megacystis (DOR 49.15, [15.28, 177.44]), bilateral hydroureteronephrosis (DOR 41.33, [13.36,164.83]), bladder thickening (DOR 13.73, [1.23, 115.20]), bilateral hydronephrosis (DOR 8.36 [3.17, 21.91]), male sex (DOR 8.08 [3.05, 22.82]), oligo- or anhydramnios (DOR 7.75 [4.23, 14.46]), and urinoma (DOR 7.47 [1.14, 33.18]) were found to be predictive of LUTO (Table 1). The predictive sensitivities and specificities however are low and wide study heterogeneity existed. Classically, LUTO is suspected in the presence of prenatally detected megacystis with a dilated posterior urethra (i.e., the keyhole sign), and bilateral hydroureteronephrosis. However, keyhole sign has been found to have modest diagnostic performance in predicting the presence of LUTO in the literature which we confirmed in our analysis. The surprisingly low specificity may be influenced by several factors, including the degree of obstruction, and the diligence of the sonographer at searching for and documenting it during the scan. As a result, providers should consider this when establishing the differential for a fetus with hydronephrosis as the presence or absence of keyhole sign does not reliably rule in or rule out LUTO. Megacystis, bilateral hydroureteronephrosis and bladder wall thickening are the most accurate predictors of LUTO. Given the significant consequences of a missed LUTO diagnosis, clinicians providing counselling for prenatal hydronephrosis should maintain a low threshold for considering LUTO as part of the differential diagnosis.