Society For Fetal Urology Research Articles

Renal Parenchyma to Hydronephrosis Area Ratio (PHAR) as a Predictor of Future Surgical Intervention for Infants With High-grade Prenatal Hydronephrosis

To explore the potential value of an objective assessment, renal parenchyma to hydronephrosis area ratio (PHAR), as an early predictor of surgery. Initial sagittal renal ultrasound (US) images of patients prospectively entered into a prenatal hydronephrosis database from January 2008 to January 2016 with baseline Society for Fetal Urology (SFU) grades III and IV prenatal hydronephrosis, without vesicoureteral reflux, were evaluated using the National Institutes of Health-sponsored image processing software. PHAR, anteroposterior diameter, SFU grade, and urinary tract dilation risk categories were contrasted with nuclear scan data (differential renal function and drainage time [t1/2]) and analyzed for predictive value in determining the decision to proceed with surgery by drawing receiver operating characteristic curves. Out of 196 infants (162 male; 138 left sided hydronephrosis), 58 (30%) underwent surgery to address obstruction. Surgical patients compared with those managed conservatively had longer t1/2 (60 vs 18 min; P < .01) and lower differential renal function (46 vs 50%; P = .01). Of the initial US parameters, PHAR (area under the curve = 0.816; P < .001) had a better predictive performance than anteroposterior diameter, SFU grade, or urinary tract dilation classification. PHAR values correlated with subsequent parameters obtained on nuclear scan. PHAR is a promising parameter that can be estimated on presentation US to help predict future need for surgery in newborns with high-grade hydronephrosis.

Associations of Initial Society for Fetal Urology Grades and Urinary Tract Dilatation Risk Groups with Clinical Outcomes in Patients with Isolated Prenatal Hydronephrosis

There are limited comparative data on the predictive value of the 2most commonly used classification systems, that is SFU (Society for Fetal Urology) hydronephrosis grades and urinary tract dilatation risk groups, in regard to the future risk of surgical intervention and the development of febrile urinary tract infection. We explored this topic in infants with isolated hydronephrosis. After screening 938 patients with prenatal hydronephrosis from 2009 to 2016 we selected 322 patients with ureteropelvic junction obstruction-like hydronephrosis for study. Hydronephrosis grades were prospectively collected at baseline, surgery and last followup. Gender, circumcision status, antibiotic prophylaxis and renal pelvis anteroposterior diameter were captured. The primary outcome was pyeloplasty and the development of febrile urinary tract infection. Comparative analyses between SFU grades/urinary tract dilatation groups and the primary outcome were performed with the Fisher exact and log rank tests. Mean ± SD age at presentation was 3.3 ± 2.6 months and mean followup was 22 ± 19 months. Pyeloplasty was performed in 32% of patients with SFU III/IV vs 31% with urinary tract dilatation 2/3. The rate of febrile urinary tract infection in patients with SFU III/IV was similar to that in those with urinary tract dilatation group 2/3 (8% vs 10%). Children with SFU III/IV showed a significantly higher rate of surgery than those with SFU I/II (32% vs 2%, p<0.01). Similar findings were seen when using urinary tract dilatation groups to compare patients at low risk (1) vs moderate/high risk (2/3). Both grading systems equally allowed for proper risk stratification and prediction of clinical outcomes based on baseline ultrasound. They correctly separated most infants who underwent surgery or in whom febrile urinary tract infection developed from those who could be treated nonsurgically. Use of the new urinary tract dilatation classification should not affect how families of children with isolated hydronephrosis are counseled regarding surgical intervention and the risk of febrile urinary tract infection.

Increasing the Reliability of the Grading System for Voiding Cystourethrograms Using Ultrasonography: An Inter-Rater Comparison.

BackgroundTo assess the effectiveness of the current vesicoureteral reflux (VUR) grading system according to the international classification of VUR (ICVUR) and to evaluate whether VUR grading accuracy could be improved by renal ultrasonography (RU) according to the Society for Fetal Urology (SFU) grading system.ObjectivesTherefore, this study assessed the accuracy of the current VCUG staging system by assessing inter-rater reliability among pediatric radiologists and urologists; it also evaluated whether accuracy is increased by RU without consensus (with respect to VCUG grading).MethodsFour pediatric urologists and four pediatric radiologists independently graded 120 voiding cystourethrograms (VCUGs). Middle VUR grades were divided into the following three groups: VUR consensus grade III (group 1), VUR consensus grade IV (group 3), and VUR non-consensus grades III and IV (group 2). All groups were compared with respect to hydronephrosis grade using RU.ResultsThe intraclass correlation coefficient (ICC) values ranging from 0.86 to 0.89 reflected good reliability. The lowest agreement was associated with middle grades (III and IV). A marked difference in sensitivity was observed between groups 1 and 3 (35% and 95%, respectively, P < 0.05), indexed by SFU hydronephrosis grade, suggesting that VCUG cases in group 2 (n = 16 at SFU 0 or 1) could be accepted as grade III, and SFU scores of 2, 3, or 4 could be considered grade IV.ConclusionsInter-rater accuracy could be improved at middle grades using renal ultrasonography (USG), which could promote communication between different specialists.

Inter-rater reliability of the APD, SFU and UTD grading systems in fetal sonography and MRI

Antenatal hydronephrosis (ANH) is frequently detected on screening obstetric ultrasonography. Common ANH grading systems include the anterior-posterior diameter (APD) and the Society for Fetal Urology (SFU) grading system. Recent developments in the management of ANH include the use of fetal magnetic resonance imaging (MRI), and a new grading system - Urinary Tract Dilation (UTD). This study reviewed patients who underwent fetal MRI and ultrasound, and compared the grading systems across these imaging modalities. Patients who underwent paired fetal MRI and ultrasound studies between January 2012 and January 2014 were included. Two pediatric urologists and a pediatric radiologist reviewed the studies. Data collected included APD, SFU grade, and UTD grade. Fleiss' kappa statistic determined the inter-rater reliability (IRR) of the SFU and UTD grading within each imaging modality. Intra-class correlation assessed the consistency of the APD measurements. Forty-seven patients and 88 renal units were evaluated. Median gestational age was 22 weeks. Kappa values of the SFU grading system indicated fair IRR for ultrasound imaging and moderate IRR for MRI imaging, while the UTD grading system reached moderate IRR for both. The IRR of the SFU grading system was improved with the use of MRI, while the UTD grading system was no different. The APD intraclass correlation coefficient improved significantly when measured by MRI. As the ultrasound SFU grade increased, the odds of the MRI SFU grade being scored higher increased by a factor of 3.7. There was no difference between ultrasound and MRI when using the UTD grading system. This study was the first to assess the UTD system in a cohort of patients who underwent paired ultrasound and MRI studies. The results suggested that the UTD system might improve IRR, compared with the SFU system. The use of fetal MRI may improve the IRR of the SFU grading system. It also found that the proportion of SFU grades was affected by the imaging modality, raising the possibility that MRI 'overcalls' the SFU grade, compared with ultrasound. This difference was not observed using the UTD grading system. The most important limitation was the selection bias favoring complex pathology with severe ANH diagnosed at an early gestational age. In this unique cohort, the UTD system improved IRR when compared to the SFU grading system. Fetal MRI improved the IRR of the SFU grading system, and improved the APD intraclass correlation. The SFU grading was likely to be higher when assessed by MRI vs ultrasound, but the UTD grade was not affected by the imaging modality.

Preoperative Risk Factors Predicting Complication Rates of Augmentation Cystoplasty Using the Modified Clavien Classification System in Pediatric Population

To evaluate preoperative predictive factors for postoperative complications of augmentation cystoplasty in children by using the modified Clavien classification system (MCCS). A retrospective review of medical records between 1994 and 2014 identified 117 children (64 males and 53 females) who underwent augmentation cystoplasty. Complications were evaluated according to the MCCS. Univariate and multivariate analyses were used to determine predictive factors affecting complication rates. The mean (SD) age was 9.3 (1.9) years and the mean (SD) hospitalization time was 9.7 (3.6) days. Patients with an adverse or unexpected event within 30 days of surgery were identified. Complications occurred in 29 (24.7%) children; 13 (11.1%) were MCCS grade I, 8 (5.1%) were grade II, 5 (4.2%) were grade III, and 3 (2.5%) were grade IV. Antireflux surgery, outlet resistance increasing procedures, Society of Fetal Urology (SFU) grades 3-4 hydronephrosis, posterior urethral valves, scoliosis, and serum creatinine greater than 1.0 mg/dL were statistically significant predictors of complications on univariate analysis. In the multivariate analysis, SFU grades 3-4 hydronephrosis, bladder neck reconstruction, and serum creatinine greater than 1.0 mg/dL were statistically significant independent predictors of complications. Augmentation cystoplasty remains a valid method of treating severe bladder dysfunction in children. SFU grades 3-4 hydronephrosis, outlet resistance increasing procedures, and serum creatinine greater than 1.0 mg/dL were the main predictive factors for postoperative complications. Use of a standardized complication grading system, such as the MCCS, should be encouraged to allow the valid comparison of complication rates between series.

Functional and morphological outcome after pyeloplasty for children with unilateral hydronephrosis

Objective To analyze the factors associated with the outcome of pyeloplasty in term of renal function and morphology improvement in children with unilateral ureteropelvic junction obstruction, in order to provide clinical evidence for the treatment of hydronephrosis in children. Methods Clinical data of 174 children who underwent unilateral dismembered pyeloplasty from January 2009 to June 2014 were retrospectively studied. Differential changes in renal function and renal morphology after pyeloplasty were assessed by serial renal scan and ultrasound. On the basis of preoperative split DRF, these patients were divided into three groups: group Ⅰ with DRF ≥40% (n = 99) , group Ⅱ with DRF 30%-40% ( n = 29) and group Ⅲwith DRF <30% (n = 46). According to their age at surgery, the children were divided into four groups, including group A aged 1-3 months (n = 52), group B aged 3 months- 3 years (n = 44), group C aged 3 - 6 years (n = 37), and group D aged more than 6 years (n = 41). Results In all 174 children, postoperative complication occurred in 7 cases, including urinary tract infection in 6 cases and renal atrophy in 1 case. A significant improvement of both function and morphology was confirmed in most patients (P<0.01). Patients in group Ⅰ showed stable renal function after operation(DRF 48.46%±4.80% vs. 50.78%±5.45%, P<0.01), of them who underwent pyeloplasty at 1-3 months of age showed the best obvious recovery of renal morphology. Renal function of patients in group II recovered obviously and most of them reached to the initial values (DRF 35.18%±2.95% vs. 43.91%±6.89%, P<0.01). While renal function of patients in group Ⅲ recovered significantly after surgery, most of them failed to restore the initial values(DRF 20.70%±6.90% vs. 33.78%±12.49%, P<0.01), and among them, the aged 1-3 months group possessed the best recovery. Moreover, the morphological improvement was similar to the functional improvement. The time for hydronephrosis recovered to less than Grade 2 of Society for Fetal Urology(SFU)was 6, 24 and over 24 months respectively in group I, Ⅱ and Ⅲ, and the renal morphology gradually improved with the increasing duration of follow-up. Conclusions The renal function and morphology of most patients improved significantly after pyeloplasty. Recovery of renal function and morphology after surgery was significantly correlated with the preoperative DRF. Early surgical intervention may improve the function and morphology recovery of the involved renal unit. Key words: Hydronephrosis; Ultrasonography; Renal dynamic imaging; retrospective study

Urinary tract infections in children with prenatal hydronephrosis: A risk assessment from the Society for Fetal Urology Hydronephrosis Registry

Risk factors for urinary tract infection (UTI) in children with prenatal hydronephrosis (PNH) are not clearly defined. Our study aim was to describe incidence and identify factors associated with UTI among a cohort of children diagnosed with PNH. Patients with confirmed PNH from four medical centers were prospectively enrolled in the Society for Fetal Urology (SFU) hydronephrosis registry between 9/2008 and 10/2015. Exclusion criteria included enrollment because of UTI, associated congenital anomalies, and less than 1-month follow-up. Univariate analysis was performed using Fisher's Exact test or Mann-Whitney U. Probability for UTI was determined by Kaplan-Meier curve. Median follow-up was 12 (IQR 4-20) months in 213 patients prenatally diagnosed with hydronephrosis. The majority of the cohort was male (72%), Caucasian (77%), and 26% had high grade (SFU 3 or 4) hydronephrosis. Circumcision was performed in 116/147 (79%) with known status, 19% had vesicoureteral reflux (VUR), and 11% had ureteral dilatation. UTI developed in 8% (n=18), 89% during their first year of life. Univariate analysis found UTI developed more frequently in females (p<0.001), uncircumcised males (p<0.01), and the presence of parenchymal renal cyst (p<0.05). Logistic regression found renal cyst to no longer be significant, but female gender a significant risk factor for development of UTI (p<0.001). Regression analysis stratified by gender found neither hydronephrosis grade nor parenchymal renal cyst to be significant risk factors for UTI development among females. However, hydronephrosis grade and circumcision status were significant risk factors for development of UTI among males (p<0.05 and p<0.01, respectively). Identification of factors associated with UTI in patients with PNH is still progressing; however, several observational studies have identified groups that may be at increased risk of UTI. Use of prophylactic antibiotics (PA), degree of kidney dilation, gender, and circumcision status all have been reported to have some degree of impact on UTI. A previous study identified risk factors for UTI as female gender, uncircumcised status, hydroureteronephrosis, and VUR, and reported that prophylaxis provided a protective effect on prevention of UTI. Our data mirror those in some respect, identifying an association of UTI with female gender and, among males, uncircumcised status, and high grade hydronephrosis. However, we were unable to demonstrate an association between UTI and the use of PA, presence of VUR, dilated ureter, or renal duplication in this observational registry.

Sonographic Renal Parenchymal Measurements for the Evaluation and Management of Ureteropelvic Junction Obstruction in Children.

To correlate sonographic renal parenchymal measurements among patients with ureteropelvic junction obstruction (UPJO) labeled society of fetal urology (SFU) hydronephrosis grades 1-4 and to examine whether sonographic renal parenchymal measurements could be used to differentiate conservative vs. surgical management. Retrospective chart review and sonographic renal parenchymal measurements (renal length, medullary pyramid thickness, and renal parenchymal thickness) were performed in patients with SFU grades 1-4 hydronephrosis secondary to UPJO managed between 2009 and 2014. Exclusion criteria included other concomitant genitourinary pathology or incomplete follow-up. Anterior-posterior renal pelvic diameter (APRPD) and radionuclide renography were also evaluated when available. One hundred four patients with UPJO underwent 244 renal and bladder ultrasound (1,464 sonographic renal parenchymal measurements in 488 kidneys). Medullary pyramid thickness and renal parenchymal thickness progressively decreased from SFU grades 1-4 (p < 0.05). A similar trend was appreciated when comparing SFU grades 1 and 2 vs. 3 and 4, as well as SFU grades 3 vs. 4 (p < 0.05). SFU grade 3 and 4 patients who underwent pyeloplasty had longer renal length in comparison to those who were managed conservatively (p < 0.02). This is the first study that evaluates these objective, quantifiable sonographic renal parenchymal measurements in children with unilateral UPJO. These sonographic renal parenchymal measurements correlate closely with worsening of hydronephrosis graded by the SFU and APRPD classification systems. Prospective studies are needed to elucidate the role of sonographic renal parenchymal measurements in the management of children with UPJO.

The Fate of Primary Nonrefluxing Megaureter: A Prospective Outcome Analysis of the Rate of Urinary Tract Infections, Surgical Indications and Time to Resolution

We examined data on a cohort of patients with primary nonrefluxing megaureter to determine risk factors for febrile urinary tract infection, indications for surgery and time to resolution. The records of patients younger than 24 months with primary nonrefluxing megaureter were prospectively captured from 2008 to 2015. Six a priori defined variables were studied, including gender, circumcision status, hydronephrosis SFU (Society for Fetal Urology) grade (low--1 and 2 vs high--3 and 4), continuous antibiotic prophylaxis use, ureteral dilatation (greater than 11 mm) and tortuosity. Univariate analyses and Cox hazard regression were done for febrile urinary tract infection risk factors. Resolution trends were analyzed using Kaplan-Meier curves. Mean ± SD age at the first clinic visit was 3.7 ± 4 months and mean followup was 26.3 ± 16.6 months. Of 80 patients with primary megaureter 66 (83%) had high grade hydronephrosis, 72 (90%) were male, 21 (26%) were circumcised and 40 (50%) had ureteral dilatation greater than 11 mm at baseline. Overall continuous antibiotic prophylaxis was prescribed to 34 patients (43%) and febrile urinary tract developed infection in 27 (34%) at a mean age of 5.8 months (median 3, range 1 to 24). Cox regression identified uncircumcised male gender (HR 3.4, 95% CI 1.1-10.7, p = 0.04) and lack of continuous antibiotic prophylaxis (HR 4.1, 95% CI 1.3-12.7, p = 0.01) as independent risk factors for febrile urinary tract infection. The 19 surgical patients (24%) had a larger mean ureteral diameter immediately preoperatively than those who did not require surgery (17 ± 5 vs 12 ± 4 mm, p <0.01). Kaplan-Meier curves showed that 85% of primary nonrefluxing megaureters that did not require surgery resolved in a median of 17 months. Febrile urinary tract infection developed in 34% of patients with primary nonrefluxing megaureter within the first 6 months of life. Circumcision and continuous antibiotic prophylaxis significantly decreased febrile urinary tract infection rates in those infants. Ureteral diameter 17 mm or greater was significantly associated with a higher rate of surgical intervention. Overall 76% of megaureters resolved during a median followup of 19 months.

Inter-rater reliability of postnatal ultrasound interpretation in infants with congenital hydronephrosis.

The most common measurements of hydronephrosis are the anterior-posterior (AP) diameter and the Society for Fetal Urology (SFU) grading systems. To date, the inter-rater reliability (IRR) of these measures has not been compared in the postnatal period. The objectives of this study were to compare the IRR of the AP diameter and the SFU grading system in infants and to determine whether ultrasound findings other than pelvicalyceal dilation are associated with higher SFU grades. Initial postnatal ultrasounds of infants seen from February 1, 2011, to January 31, 2012, with a primary diagnosis of congenital hydronephrosis were included for review. Ultrasound images were de-identified and reviewed by four pediatric urologists. IRR was calculated using the intraclass correlation (ICC) measure. A paired t test was used to compare ICCs. Associations between SFU grade and other ultrasound findings were tested using Chi-square or Fisher's exact tests. A total of 112 kidneys in 56 patients were reviewed. IRR of the SFU grading system was high (right kidney ICC = 0.83, left kidney ICC = 0.85); however, IRR of AP diameter measurement was higher (right kidney ICC = 00.97, left kidney ICC = 0.98; p < 0.001). Renal asymmetry (p < 0.001), echogenicity (p < 0.001), and parenchymal thinning (p < 0.001) were significantly associated with SFU grade 4 hydronephrosis on bivariable and multivariable analysis. The SFU grading system is associated with excellent IRR, although the AP diameter appears to have higher IRR. Physicians may consider ultrasound findings that are not explicitly included in the SFU system when assigning hydronephrosis grade, which may lead to variability in use of this classification system.

A New Grading System for the Management of Antenatal Hydronephrosis.

Standard clinical assessments do not predict surgical intervention in patients with a moderate degree of upper tract hydronephrosis. This study investigated whether combined measures of renal calyceal dilation and anteroposterior diameter (APD) of the renal pelvis at the first postnatal ultrasound better predict surgical intervention beyond standard assessments of the APD or Society of Fetal Urology (SFU) grading system. A retrospective cohort of 348 children with antenatal hydronephrosis followed from 2003 to 2013 were studied. Using Cox regression, the risk for surgery by APD, SFU, and combined grading on the basis of the first postnatal ultrasound was calculated. The predictive capability of each grading system for surgery was determined by calculating the positive likelihood ratio (LR+). The combination of APD≥6-9 mm and diffuse caliectasis had a hazard ratio (HR) of 19.5 (95% confidence interval [95% CI], 3.94 to 96.9) versus 0.59 (95% CI, 0.05 to 6.53) for APD≥6-9 mm alone and a similar risk of 8.9 for SFU grade 3 (95% CI, 3.84 to 20.9). The combination of APD≥9-15 mm and diffuse caliectasis had an HR of 18.7 (95% CI, 4.36 to 80.4) versus 1.75 (95% CI, 0.29 to 10.5) for APD≥9-15 mm alone. The LR+ for surgery for diffuse caliectasis and APD≥6-9 mm was higher than for APD≥6-9 mm alone (HR=2.62; 95% CI, 0.87 to 7.94 versus HR=0.04; 95% CI, 0.01 to 0.32) and was higher for APD≥9-15 mm and diffuse caliectasis than APD≥9-15 mm alone (HR=2.0; 95% CI, 1.15 to 3.45 versus HR=0.14; 95% CI, 0.04 to 0.43). Both combined groups of moderate hydronephrosis (APD≥6-9 mm or ≥9-15 mm with diffuse caliectasis) had only slightly higher LR+ than SFU grade 3 (HR=1.89; 95% CI, 1.17 to 3.05). These results suggest a grading system combining APD and diffuse caliectasis distinguishes those children with moderate degrees of upper tract hydronephrosis that are at higher risk of surgery.

Teaching of the Society for Fetal Urology grading system for pediatric hydronephrosis is improved by e-Learning using Computer Enhanced Visual Learning (CEVL): A multi-institutional trial

It is unclear how clinicians learn to grade pediatric hydronephrosis (HN) and how effective their training has been. We sought to: 1. Assess how clinicians learn to grade HN and their confidence in their training and abilities and 2. To assess Computer Enhanced Visual Learning (CEVL) e-Learning to learn the Society for Fetal Urology (SFU) grading system for pediatric HN. A multi-institutional online survey was distributed to pediatric urologists, nephrologists, and radiologists. Respondents used a 6-point Likert scale (0 = not confident to 5 = very confident) to assess their confidence in knowledge of the criteria, indications, and ability to grade HN, and how they learned to grade. Participants assigned SFU grades to 15 neonatal ultrasounds (US). A CEVL module on the SFU grading system was accessed and a post-CEVL survey completed. Changes in confidence and accuracy of grading were compared before and after CEVL e-Learning. The most common method of learning was "casually during training" (44.5%). Significant increases in confidence in knowledge of criteria, indications, and ability to grade, as well as the accuracy of grading were seen following CEVL e-Learning (Figure A and B). Although the SFU grading system is considered the predominant grading system for HN, its application in clinical practice has been inconsistent. While this may be due to the grading system itself, it is possible that deficient training and confidence are the root causes. Our data supports this by demonstrating that most clinicians receive only casual training and accordingly, report low confidence in their knowledge and ability to grade HN. Therefore, we conclude that there exists a strong need to improve the teaching of the SFU grading system. e-Learning has been shown to be effective in teaching difficult topics and skills. We demonstrate that e-Learning with CEVL is effective in increasing both the confidence and accuracy of SFU grading of pediatric HN. Limitations of our study include a small sample size, low response rate, and discrepant participation. Furthermore, we did not assess the extent to which the CEVL module was used or include a control group learning through traditional means. Therefore, we were unable to evaluate the efficiency of learning or be certain that the improvements seen were derived exclusively from CEVL. Current training in SFU grading of HN is mostly unstructured and inaccurate grading is common. Learners who use CEVL show improvements in their confidence and ability to SFU grade HN.

Renal tract abnormalities missed in a historical cohort of young children with UTI if the NICE and AAP imaging guidelines were applied

In a historical cohort of children with a urinary tract infection (UTI) who had already undergone all the imaging procedures, the aim was to determine renal tract abnormalities which would have been missed had we implemented the new guidelines from the National Institute for Health and Care Excellence in the United Kingdom (NICE) or the American Academy of Pediatrics (AAP). After a UTI episode, forty-three children (28 females, 65%) aged between 2 months and 2 years presenting at two general hospitals with a febrile UTI before 2008 underwent all the recommended imaging studies predating the new guidelines. Hydronephrosis was defined and graded according to the Society for Fetal Urology (SFU) classification. Hydronephrosis grade II (mild pelvicalyceal dilatation), grade III (moderate dilatation), and grade IV (gross dilatation with thinning of the renal cortex), duplication, vesicoureteral reflux (VUR) grade II and above, renal scarring and reduced renal uptake (<45%) on technetium-99m-labeled dimercaptosuccinic acid (DMSA) scintigraphy were considered significant abnormalities. We calculated the proportion of abnormalities which would have been missed had the new guidelines been used instead. The median of age was 7.6 months (mean 8.7, range 2-24 months), with the majority (n = 37, 86%) being under 1 year of age. Ultrasound (US) showed hydronephrosis in 14 (32%), all grade II. A voiding cystourethrogram (VCUG) was performed in all and showed VUR ≥ grade II in 16 (37%), including eight children (19%) where it was bilateral. DMSA scan showed scarring in 25 children (58%) of whom 11 (26%) had bilateral scars. Reduced differential renal uptake was present in 10 children (23%). Of the 29 children with normal US, 18 (62%) had renal scarring and nine (31%) had VUR ≥ grade II. The NICE guidelines would have missed 63% of the children with VUR ≥ grade II, including a high proportion of grades IV and V VUR, 44% of the children with renal scarring, and 20% of the children with decreased renal uptake, including some children with bilateral renal scarring and with decreased renal uptake. The AAP guidelines would have missed 56% of the children with VUR ≥ grade II, including a high proportion of grades IV and V VUR, and all children with renal scarring as well as those with decreased renal uptake. The prevalence of renal tract abnormalities missed by the new guidelines is high. They should be used with full awareness of their limitations.

Sonographic Evaluation of Hydronephrosis in the Pediatric Population

Standardized protocols exist for diuretic renography. There are no specific guidelines regarding hydration before renal sonography. This study assessed the importance of the hydration status by sonographic measurements of the anteroposterior diameter and its effect on Society for Fetal Urology (SFU) hydronephrosis grading. Children aged 6 weeks to 16 years (mean age, 22 months) with unilateral SFU grade 3 or 4 hydronephrosis requiring diuretic renal scintigraphy were recruited to undergo prehydration and posthydration renal sonography. Hydrated diuretic renal scintigraphy, or "well-tempered" renography, was then performed. Renal sonograms were reviewed by a blinded pediatric radiologist and pediatric urologist. Two-sided statistical tests assessed whether SFU grades and the anteroposterior diameter changed significantly after hydration. Among 67 kidneys, the pediatric urologist (L.P.M.) and pediatric radiologist (V.J.R.) reported no SFU grade change in 45 (67%) and 52 (78%) kidneys after hydration. In kidneys that changed, the posthydration grade was more likely to be higher. This difference was statistically significant (14 of 22 and 13 of 15 differences were higher grades after hydration for L.P.M. and V.J.R., respectively; P= .06; P= .007). Most kidneys that changed with hydration differed by only 1 SFU grade. Differences greater than 1 grade were seen in 5 control kidneys, which increased from SFU grade 0 to 2. The mean anteroposterior diameter increased significantly between prehydration and posthydration sonography for both hydronephrotic kidneys (1.46 versus 1.72 cm; P< .001) and control kidneys (0.22 versus 0.39 cm; P= .019), but did not correlate with increased SFU grades. Hydration does have a substantial effect on the anteroposterior diameter, but it does not correlate with a substantial effect on the SFU grade; therefore, well-tempered sonography seems unnecessary.

Predictors for the need of surgery in antenatally detected hydronephrosis due to UPJ obstruction – A prospective multivariate analysis

Disagreement exists over the ability of different diagnostic tests to define obstruction, indications and timing of surgery and which patients will benefit from surgical intervention in antenatal hydronephrosis (ANH) due to ureteropelvic junction obstruction (UPJO). We try to find a way to predict which patients of ANH due to UPJO will eventually need surgery during conservative management. Prospective single centre study involving 122 renal units at a referral centre in India. Patients on conservative management were followed using a standard protocol and operated for pre-defined indications defining failure of conservative management. Patients who underwent surgery were compared with the non-operated group in terms of sex, side, baseline grade of hydronephrosis, maximum anterioposterior diameter on first postnatal ultrasound and differential renal function on first renal scan. A total of 109 renal units qualified for conservative management. Of those, 23.9% required operative intervention during follow-up. Median time to failure of conservative management was 37 weeks. The median follow-up of non-operated cases was 54 months. Univariate analysis revealed that society of fetal urology (SFU) grade of hydronephrosis, anteroposterior diameter (APD), cortical thickness (CT), and pre-operative differential renal function (DRF) had a significant association with surgery (P < 0.05). Multivariate analysis revealed APD and pre-operative DRF as the only independent predictors for requiring surgery, while CT and initial SFU grade of hydronephrosis were not. Receiver operating curve analysis showed that an APD of 24.3 mm could predict the need for surgery, with a sensitivity of 73.1% and a specificity of 88.0%. APD and DRF are the predictive factors for surgery. We stop short of recommending surgery only on the basis of APD. Instead we recommend that efforts be made to improve the specificity of this criterion, or by using APD in perspective with the differential renal function. We can reduce the burden of investigations in those with APD <24 mm while those with APD >24 mm can be more comprehensively monitored.

Diagnostic accuracy of neonatal kidney ultrasound in children having antenatal hydronephrosis without ureter and bladder abnormalities

To determine the diagnostic accuracy of anteroposterior renal pelvic diameter (APD) measurement and the society for fetal urology (SFU) grading in neonatal ultrasonography (USG) for detecting uropathy in newborns having antenatal isolated hydronephrosis (IH), characterized by hydronephrosis without ureter and bladder abnormalities, and to study time to resolution and factors predicting resolution of insignificant hydronephrosis. Ninety-six healthy newborns (129 kidneys) with IH, who underwent USG at age 7-30 days and voiding cystourethrography (VCUG) in conjunction with diuretic renography (DR) if APD > 10 mm or SFU grade 3-4 in neonatal USG, and at least a 12-month follow-up were divided into significant and insignificant hydronephrosis using the combined data of sequential USG, VCUG, and DR as the reference standard. Areas under the receiver operating characteristic plots (95 % CI) were 0.86 (0.79-0.94) versus 0.81 (0.73-0.89); p = 0.08, and 87.6 versus 79.8 % of cases were correctly classified, for APD ≥ 16 mm versus SFU grade 4, respectively. Ureteropelvic junction obstruction (UPJO) was the most common uropathy diagnosed. Of 85 kidneys with insignificant hydronephrosis, 57 underwent spontaneous resolution. The resolution rates were 24, 40, and 68 % at age 6, 12, and 24 months, respectively. APD was the only independent factor predicting resolution with the hazard ratio of 0.83 (95 % CI 0.74-0.92; p = 0.001). In IH, neonatal USG was a useful diagnostic tool to detect uropathy, mainly UPJO. Further investigation should be recommended when APD ≥ 16 mm or SFU grade 4.

Factors associated with surgical intervention in children with high-grade congenital hydronephrosis

Purpose: A lack of uniform guidelines regarding ureteropelvic junction obstruction may be associated with demographic variations in pyeloplasty timing. This study objective was to determine if children who undergo surgery are more likely to be of minority race. Materials and methods: Children with Society for Fetal Urology (SFU) 3–4 hydronephrosis were reviewed. Demographic and clinical characteristics were abstracted. Bivariable associations between clinical/demographic characteristics and pyeloplasty versus observation as well as follow-up findings were assessed with chi-square testing. The bivariable relationship between race and time from first clinic visit to surgery was evaluated by Kaplan-Meier curve. Multivariable logistic regression was performed to estimate the relationship between clinical characteristics and management decision. Results: Thirty-nine patients underwent pyeloplasty and 50 were observed. There were no differences in demographics, including race/ethnicity. Factors associated with surgery included higher SFU grade ( p = 0.01), preoperative MAG3 ( p = 0.02), and T½ &gt;20 ( p = 0.01). On multivariate analysis, MAG3 T½ &gt;20 was associated with surgery (OR = 0.20, 95% CI: 0.07–0.61). Median time to surgery for whites versus non-whites was not significant (232 vs 208 days, p = 0.16). Conclusions: In our cohort, the decision to perform pyeloplasty is associated with clinical rather than demographic characteristics. Despite controversy regarding T½ interpretation, delayed radiotracer clearance remained a significant predictor of surgery.

Characterizing upper urinary tract dilation on ultrasound: a survey of North American pediatric radiologists' practices.

Radiologists commonly evaluate children first diagnosed with urinary tract dilation on prenatal ultrasound (US). To establish how North American pediatric radiologists define and report findings of urinary tract dilation on US. A web-based survey was sent to North American members of the Society for Pediatric Radiology (SPR) from January to February 2014. Reporting practices and interpretation of three image-based cases using free text were queried. Responses to close-ended questions were analyzed with descriptive statistics, while free-text responses to the three cases were categorized and analyzed as (1) using either descriptive terminology or an established numerical grading system and (2) as providing a quantitative term for the degree of dilation. Two hundred eighty-four pediatric radiologists answered the survey resulting in a response rate of 19.0%. There is a great variety in the terms used to describe urinary tract dilation with 66.2% using descriptive terminology, 35.6% using Society for Fetal Urology (SFU) grading system and 35.9% measuring anterior-posterior diameter (APD) of the renal pelvis. There is no consensus for a normal postnatal APD or the meaning of hydronephrosis. For the same images, descriptions vary widely in degree of severity ranging from normal to mild to severe. Similar variability exists among those using the SFU system. Ninety-seven percent say they believe a unified descriptive system would be helpful and 87.7% would use it if available. Pediatric radiologists do not have a standardized method for describing urinary tract dilation but have a great desire for such a system and would follow it if available.

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

ObjectiveUrinary tract (UT) dilation is sonographically identified in 1–2% of fetuses and reflects a spectrum of possible uropathies. There is significant variability in the clinical management of individuals with prenatal UT dilation that stems from a paucity of evidence-based information correlating the severity of prenatal UT dilation to postnatal urological pathologies. The lack of correlation between prenatal and postnatal US findings and final urologic diagnosis has been problematic, in large measure because of a lack of consensus and uniformity in defining and classifying UT dilation. Consequently, there is a need for a unified classification system with an accepted standard terminology for the diagnosis and management of prenatal and postnatal UT dilation. MethodsA consensus meeting was convened on March 14–15, 2014, in Linthicum, Maryland, USA to propose: 1) a unified description of UT dilation that could be applied both prenatally and postnatally; and 2) a standardized scheme for the perinatal evaluation of these patients based on sonographic criteria (i.e. the classification system). The participating societies included American College of Radiology, the American Institute of Ultrasound in Medicine, the American Society of Pediatric Nephrology, the Society for Fetal Urology, the Society for Maternal-Fetal Medicine, the Society for Pediatric Urology, the Society for Pediatric Radiology and the Society of Radiologists in Ultrasounds. ResultsThe recommendations proposed in this consensus statement are based on a detailed analysis of the current literature and expert opinion representing common clinical practice. The proposed UTD Classification System (and hence the severity of the UT dilation) is based on six categories in US findings: 1) anterior-posterior renal pelvic diameter (APRPD); 2) calyceal dilation; 3) renal parenchymal thickness; 4) renal parenchymal appearance; 5) bladder abnormalities; and 6) ureteral abnormalities. The classification system is stratified based on gestational age and whether the UT dilation is detected prenatally or postnatally. The panel also proposed a follow-up scheme based on the UTD classification. ConclusionThe proposed grading classification system will require extensive evaluation to assess its utility in predicting clinical outcomes. Currently, the grading system is correlated with the risk of postnatal uropathies. Future research will help to further refine the classification system to one that correlates with other clinical outcomes such as the need for surgical intervention or renal function.

Resolution rate of isolated low-grade hydronephrosis diagnosed within the first year of life

ObjectiveDiagnosis of low-grade hydronephrosis often occurs prenatally, during evaluation after urinary tract infection (UTI), or imaging for non-urologic reasons within the first year of life. Its significance in terms of resolution, need for antibiotic prophylaxis, or progression to surgery remains uncertain. We hypothesized that isolated low-grade hydronephrosis in this population frequently resolves, UTIs are infrequent, and progression to surgical intervention is minimal. Patients and methodsChildren <12 months old diagnosed hydronephrosis (Society for Fetal Urology [SFU] grade 1 or 2) between January 2004 and December 2009 were identified by ICD9 code. Patients with other urological abnormalities were excluded. Stability of hydronephrosis, UTI (≥100,000 CFU/mL bacterial growth) or need for surgical intervention was noted. ResultsOf 1496 infants with hydronephrosis, 416 (623 renal units) met inclusion criteria. Of 398 renal units with grade 1 hydronephrosis, 385 (96.7%) resolved or remained stable. Only 13 (3.3%) worsened, of which one underwent ureteroneocystostomy. Of 225 renal units with grade 2 hydronephrosis, 222 (98.7%) resolved, improved or remained stable, three (1.3%) worsened, of which one required pyeloplasty. Only 0.7% of patients in the ambulatory setting had a febrile UTI. ConclusionsLow-grade hydronephrosis diagnosed within the first year of life remains stable or improves in 97.4% of renal units. Given the low rate of recurrent UTI in the ambulatory setting, antibiotic prophylaxis has a limited role in management.