Revised guidelines on management of antenatal hydronephrosis

Role of Urinary Biomarkers in the Postoperative Follow-Up of Ureteropelvic Junction Obstruction: A Preliminary Report

BACKGROUND

While the role of urinary biomarkers in differentiating non-obstructive dilatation (NOD) from ureteropelvic junction obstruction (UPJO) has been documented, there are limited reports on their utility in post-operative follow-up. This study aimed to document the values of urinary biomarkers: carbohydrate antigen (CA 19-9), neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule (KIM-1) following pyeloplasty.

METHODS

In this prospective study, children with UPJO (those who worsened on ultrasound, or on renogram, or became symptomatic underwent dismembered pyeloplasty). Urinary biomarkers NGAL, KIM-1, and CA19-9 were measured before pyeloplasty, at 6-weeks and 6-months after stent removal. Surgical outcomes were assessed by reduction in antero-posterior diameter (APD) on ultrasound and improvement in differential renal function (DRF)/washout pattern on renogram.

RESULTS

All patients in this study (n = 34) showed improvement after pyeloplasty. Urinary CA 19-9 levels (U/ml) showed a significant fall following pyeloplasty (p = 0.001) from 193 (147-308) before surgery to 34 (23-55) (6 weeks post-op) and 12 (10-13) (6 months post-op). Urinary NGAL (pg/ml) showed a significant decline following pyeloplasty (p = 0.001) from 38 (25-62) before surgery to 22 (14-29) (6 weeks post-op) and 13 (9-18) (6 months post-op). Urinary KIM-1 (pg/ml) values also showed a significant reduction following pyeloplasty (p = 0.001) from 799 (503-847) (before surgery) to 187 (167-236) (6 weeks post-op) and 121 (106-173) (6 months post-op). Biomarker levels had strong positive correlation with pelvis size (R: 0.85, 0.77 and 0.65 for CA 19-9, NGAL and KIM 1 respectively with p < 0.001) and negative correlation (R: -0.72, -0.68 and -0.52 for CA 19-9, NGAL and KIM 1 respectively with p < 0.001) with renal function.

CONCLUSION

A decline in postoperative urinary biomarker levels was associated with prompt resolution of hydronephrosis after pyeloplasty. We did not have any failures in this preliminary study and further larger studies are warranted.

Clinical Characteristics and Outcomes of Children with Unilateral Multicystic Dysplastic Kidney: A Cohort Study

OBJECTIVES

To study the clinical profile and outcomes of children with unilateral multicystic dysplastic kidney (MCDK).

METHODS

We assessed the clinical features and extrarenal manifestations in children with unilateral MCDK. These children were followed up to ascertain involution, compensatory hypertrophy and progression of chronic kidney disease (CKD) stage.

RESULTS

We enrolled 106 children with unilateral MCDK which was detected antenatally in 98 (92.4%), while evaluating for urinary tract infection in three (2.8%), and incidentally in five (4.7%) children. Abnormalities in the contralateral kidney and extrarenal manifestations at initial presentation were detected in 30 (28.3%) and 15 (14.2%), respectively. At a median (IQR) follow-up of 60 (32, 87) months, 34 (32.1%) children demonstrated complete involution of the MCDK, while 72 (67.9%) showed compensatory hypertrophy in the contralateral kidney. The median age at involution of MCDK was 48.5 (33, 86.5) months. Twenty-two (20.7%) children had non-regression of MCDK, and two (1.9%) underwent nephrectomy. Eight (7.5%) children developed hypertension and two children were detected to have proteinuria. One child, each, progressed to CKD stage 2 and stage 3a; and another child (0.9%) progressed to end stage kidney disease. None of the patients developed malignant transformation.

CONCLUSIONS

Majority of cases (92.4%) of MCDK had been detected antenatally. The rate of involution was 32.1% at a median follow-up of 60 months. Although, 28.3% of cases of MCDK had abnormalities in the contralateral kidney, progression of CKD to a higher stage occurred only in three (2.8%) cases.

Impact of antibiotic prophylaxis on urinary tract infection recurrence in children Rapid review

INTRODUCTION

Given the potential consequences associated with urinary tract infections (UTIs), it has become standard practice to use continuous antibiotic prophylaxis (CAP) in children, even if controversial. We reviewed the effectiveness of CAP on recurrent UTI in a pediatric population to determine if equipoise remains and allows for a placebo control group to study the effectiveness of the vaccine MV140.

METHODS

We completed a rapid review. We searched Medline, Embase and the Cochrane Library and data extraction was completed by a single reviewer. Our search criteria were 2005-2022, English and French language, randomized controlled trials (RCTs) and systematic reviews only. The population was 19 years and younger, including: vesicoureteral reflux (VUR), congenital anomalies of the kidneys and urinary tracts (CAKUT), and bladder and bowel dysfunction (BBD).

RESULTS

Three RCTs and three systematic reviews found a benefit for CAP, mostly for a population with VUR, and those with severe VUR have more benefit. Most studies were not able to show a difference in the rate of UTIs or new renal scars (NRS). Three RCTs found a deleterious effect with CAP. Other studies were able to prove a benefit for patients with dilatation of the urinary tract without obstruction and high-grade VUR combined with BBD. The major adverse event found was antimicrobial resistance.

CONCLUSIONS

High-risk patients benefit from CAP. The potential consequences of UTIs makes it unethical to use a placebo-only control group for them; however, CAP use seems difficult to justify in a low-risk population.

Does Age Influence the Functional Recovery after Infant Pyeloplasty?

Purpose

The purpose was to study the correlation between age at surgery and functional recovery after infant pyeloplasty.

Materials and Methods

All infants who underwent pyeloplasty were analyzed retrospectively in this multicenter study. Anteroposterior diameter (APD) >2 cm, split renal function (SRF) <40%, and Society of Fetal Urology (SFU) grade 3-4 were surgical indications. Based on the age at pyeloplasty, they were divided into Group 1 (1-3 months) and Group 2 (4-12 months). APD and SRF were compared before and after surgery in both groups. The fractional recoverable function (post-SRF-pre-SRF)/(50-pre-SRF) ×100 was correlated with age.

Results

Fifty-one infants underwent pyeloplasty (mean age: 1.6 months - Group 1 and 7.2 months - Group 2). The mean APD decreased from 3 cm to 1.2 cm in Group 1 while 2.8 cm to 2 cm in Group 2 (P = 0.001). The mean SRF increased from 32.28% to 42.81% in Group 1 while 31%-34.18% in Group 2. SRF recovery was significantly higher in Group 1 compared to Group 2 (P = 0.001). Regression analysis showed a weak negative correlation (r = -0.2792) between age at surgery and renal function improvement.

Conclusion

Functional recovery after pyeloplasty is better when done earlier (1-3 months), as this gives the growing kidney the best opportunity to recover.

Comparison of Urinary Biomarkers in Diagnosis of Ureteropelvic Junction Obstruction and Differentiation from Nonobstructive Dilatation

Background and Aims

Differentiation of nonobstructive dilatation (NOD) from ureteropelvic junction obstruction (UPJO) is a challenge in children with antenatally detected hydronephrosis. The aim of this study is to compare the utility of urinary biomarkers: carbohydrate antigen (CA 19-9), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule (KIM) in diagnosing UPJO.

Methods

A prospective study was conducted after obtaining ethical clearance between 2021 and 2022. Group 1 - control group (n = 30): children with normal antenatal ultrasound with no urinary symptoms. Group 2 - study group (n = 48): children with unilateral hydronephrosis: Group 2a - NOD (n = 24): children stable on ultrasound and diuretic renogram and Group 2b - UPJO (n = 24): children who worsened to Grade 4 hydronephrosis on ultrasound/worsening of differential renal function (10% drop) on renogram who underwent pyeloplasty. Urinary biomarkers NGAL, KIM-1, and CA 19-9 were measured using the enzyme-linked immune absorbent assay method.

Results

The urine CA 19-9 level was 128.05 ± 4.08 U/mL in the UPJO group, and this was significantly higher (P = 0.001) than NOD, 70.29 ± 4.41, and controls, 1.91 ± 1.57. The urine NGAL level was 21.41 ± 4.44 pg/mL in UPJO, and this was significantly higher than controls, 2.669 ± 0.513, but not NOD, 24.55 ± 2.67. The urine KIM level was 817 ± 15.84 pg/mL in the UPJO group, and this was significantly higher than controls, 285 ± 8.10, but not NOD, 768.23 ± 15.12. Receiver operating characteristic analysis of CA 19-9 revealed a urine biomarker cutoff of 95 U/mL for diagnosing UPJO (sensitivity 95%; specificity 96%; and area under the curve 0.99).

Conclusions

CA 19-9 is a superior marker compared to NGAL and KIM in differentiating UPJO from NOD. Further studies with larger numbers are warranted.

Perinatal Management of Pregnancies with Fetal Congenital Anomalies: A Guide to Obstetricians and Pediatricians

BACKGROUND

Congenital anomalies are responsible for approximately 20% of all neonatal deaths worldwide. Improvements in antenatal screening and diagnosis have significantly improved the prenatal detection of birth defects; however, these improvements have not translated into the improved neonatal prognosis of babies born with congenital anomalies.

OBJECTIVES

An attempt has been made to summarise the prenatal interventions, if available, the optimal route, mode and time of delivery and discuss the minimum delivery room preparations that should be made if expecting to deliver a fetus with a congenital anomaly.

METHODS

The recent literature related to the perinatal management of the fetus with prenatally detected common congenital anomalies was searched in English peer-reviewed journals from the PubMed database to work out an evidence-based approach for their management.

RESULTS

Fetuses with prenatally detected congenital anomalies should be delivered at a tertiary care centre with facilities for neonatal surgery and paediatric intensive care if needed. There is no indication for preterm delivery in the majority of cases. Only a few congenital malformations, like highrisk sacrococcygeal teratoma, congenital lung masses with significant fetal compromise, fetal cerebral lesions or neural tube defects with Head circumference >40 cm or the biparietal diameter is ≥12 cm, gastroschisis with extracorporeal liver, or giant omphaloceles in the fetus warrant caesarean section as the primary mode of delivery.

CONCLUSION

The prognosis of a fetus with congenital anomalies can be significantly improved if planning for delivery, including the place and time of delivery, is done optimally. A multidisciplinary team should be available for the fetus to optimize conditions right from when it is born.

Non-surgical management in children with non-refluxing primary megaureter: a systematic review and meta-analysis

BACKGROUND

Children with non-refluxing primary megaureter are mostly managed by a watchful approach with close follow-up and serial imaging.

OBJECTIVES

This systematic review and meta-analysis aimed to determine whether there is sufficient evidence to support the current non-surgical management strategy in these patients.

DATA SOURCES

A comprehensive search including electronic literature databases, clinical trial registries, and conference proceedings was performed.

DATA SYNTHESIS METHODS

Outcomes were estimated as pooled prevalence. If meta-analytical calculations were not appropriate, outcomes were provided in a descriptive manner.

RESULTS

Data from 8 studies (290 patients/354 renal units) were included. For the primary outcome, differential renal function estimated by functional imaging, meta-analysis was impossible due to reported data not being precise. Pooled prevalence for secondary surgery was 13% (95% confidence interval: 8-19%) and for resolution 61% (95% confidence interval: 42-78%). The risk of bias was moderate or high in most studies.

LIMITATIONS

This analysis was limited by the low number of eligible studies with few participants and high clinical heterogeneity, and the poor quality of the available data.

CONCLUSIONS

The low pooled prevalence of secondary surgical intervention and high pooled prevalence of resolution may support the current non-surgical management in children with non-refluxing primary megaureter. However, these results should be interpreted cautiously due to the limited available body of evidence. Future studies should overcome existing limitations of imaging methods by using standardized, comparable criteria and report outcome parameters in a quantitative manner. This would allow more sufficient data synthesis to provide evidence-based recommendations for clinical decision-making and counseling.

SYSTEMATIC REVIEW REGISTRATION

The protocol was registered on PROSPERO under CRD42019134502.

Can pyeloplasty restore normal renal function in patients with severe unilateral ureteropelvic junction obstruction and DRF < 35

PURPOSE

To assess the outcome of successful pyeloplasty in infants with Ureteropelvic Junction Obstruction (UPJO) and a differential renal function of (DRF) < 35% whether they can attain normal postoperative renal function or not.

METHODS

All children who were diagnosed with antenatal hydronephrosis due to UPJO were presented to our institutions and were prospectively followed up. Pyeloplasty was performed based on predefined indications such as: initial DRF ≤40%, progression of hydronephrosis, and febrile urinary tract infection (UTI). A total of 173 children, who had successful surgical intervention due to impaired DFR, were divided according to their pre-intervention DRF value as follows: DRF <35% (group I) and DRF 35-40% (group II). The renal morphology and function changes were recorded and used for comparison between both groups.

RESULTS

Group I was comprised of 79 patients, and group II included 94 patients. Pyeloplasty achieved significant improvement in the anatomical and functional indices in both groups (p-value <0.001). The degree of improvement in Anteroposterior diameter (APD) and cortical thickness was comparable in both groups (P-value, 0.64 and 0.44 respectively). While the improvement in the DRF was significantly higher in group I (16.06 ± 6.6) than in group II (6.25 ± 2.66) (P-value <0.001). Despite that, a significantly higher percentage of infants in group II (61.7%) achieved normal final DRF compared with only (10.1%) in group I (Figure).

CONCLUSION

Even in severely impaired renal function (<35%), successful pyeloplasty can recover a significant part of lost renal function. However, most of these patients do not achieve normal postoperative renal function.

Pelvico-Vesicostomy for Horseshoe Kidney With Severe Right Ureteric Stricture and Bilateral Hydronephrosis

Ureteropelvic junction (UPJ) obstruction is the most common renal anomaly observed in infants with congenital hydronephrosis. The present study presents a five-month-old infant with severe right ureteropelvic obstruction. Anderson-Hynes pyeloplasty intervention significantly improved renal function. The study concludes that early surgical intervention is the definitive treatment for avoiding kidney impairment and its complications.

Correlation of Plasma Renin Activity Values and Resistive Index on Ultrasound Doppler with Findings of Renal Dynamic Scan in Patients with the Society of Fetal Ultrasound grades 3 and 4 Unilateral Hydronephrosis

BACKGROUND

Renal dynamic scans (RDS) despite being considered the gold standard for the diagnosis of pelvic ureteric junction obstruction (PUJO), fail to help resolve the dilemma about management issues in many patients. Multiple invasive and noninvasive methods are being studied to help the decision-making in these patients. We did this study to find correlation of plasma renin activity (PRA) values and resistive index (RI) on Doppler ultrasound with findings of RDS in patients with the Society for Fetal Urology (SFU) Grades 3 and 4 unilateral hydronephrosis (HDN) and also to determine the cut-off values of PRA and RI that could categorically acknowledge the success of pyeloplasty.

METHODOLOGY

Twenty patients with SFU Grades 3 and 4 unilateral HDN due to PUJO were enrolled. Demographic details were recorded. All underwent Anderson-Hynes dismembered pyeloplasty. Based on the follow-up RDS scans, these patients could fall into one of three categories- improved (successful), status quo, or deteriorated (unsuccessful). Outcomes were compared based on RDS (split renal function [SRF]), ultrasonography, and Doppler findings were done at 3 months of postoperative period.

RESULTS

Follow up period was 3 months after Pyeloplasty. Seventeen patients had successful outcomes based on RDS findings, 12 had improvement in SRF (>5%), and 6 had normal drainage curves (t-t1/2<10 min). Three patients had indeterminate curves (t-t1/2between 10 to 20 min). Four had improvement on both the criteria, i.e., SRF and drainage curves. Among the three patients who showed no improvement in RDS, two were in "status quo" category and one patient showed deterioration. Seventeen patients also showed improvement in PRA and RI. No significant correlation between PRA and RI with SRF could be established. However, PRA was found to have good concordance with RDS (90%).

CONCLUSION

No significant correlation could be demonstrated between SRF and the respective values of PRA and RI. However, PRA could act as an adjunct to predict the early success of pyeloplasty in view of good concordance with RDS. A larger trial with bigger cohort of patients is required to confirm our contention.

Timing of delivery in antenatal fetal hydronephrosis: a snap shot social media survery of obstetric and fetal medicine practice

OBJECTIVES

To identify when obstetricians would deliver a fetus with antenatal hydronephrosis and normal liquor. Designed as snap-shot survey. Setting: Survey Monkey link. Population/sample were obstetrics and fetal medicine consultants who received the survey link via closed professional forums on the North West Coast Maternity Clinical Network, Facebook, and publicly on Twitter.

METHODS

Survey link publicised as above, obstetric consultants were asked at what gestation would they deliver a fetus with antenatal hydronephrosis and normal liquor; and what criteria would they use to make that decision. Main outcome measures were number of years in practice, gestation at delivery, anteroposterior diameter (APD) of renal pelvis.

RESULTS

A total of 44/102 respondents (43%) would deliver prior to 40 weeks (median no. of years as consultant 10 years [IQR 5-17]) vs. those who would not (median years as consultant 5.5 [IQR 3-12]). Re APD threshold of delivery: 17 indicated delivery if the APD were 20 mm, 10 if it were 21-30 mm and 16 if it were >30 mm. Re gestation at which they would deliver: 13 indicated 37-38 weeks, 13 indicated 38-39 weeks and 17 indicated 39-40 weeks. Reasons selected for delivery before term were obstetric anxiety n=2, maternal request n=2, maternal anxiety n=2 and concern about fatal renal damage/renal damage n=34.

CONCLUSIONS

A surprising number of respondents would consider early delivery of a fetus with hydronephrosis and normal liquor despite the lack of evidence of benefit. The evidence supporting term delivery means that early term delivery is only indicated for obstetric reasons in this scenario.

Extraspinal findings prevalence and clinical significance in 4250 lumbar spine MRI exams

To assess extraspinal findings (ESFs) prevalence in lumbar spine MRI, including clinically significant findings using a systematic approach, and to determine their reporting rate. Lumbar spine MRI scans were retrospectively reviewed over 18 months by two radiologists. Reading discrepancies were resolved by consensus. ESFs were classified according to the involved system, clinical diagnosis, and clinical significance. The reporting rate was estimated by referring to the original report. There were 1509 ESFs in 1322/4250 patients with a substantial agreement between the two radiologists (kappa = 0.8). Almost half (621/1322) were in the 45–60 age group. Females represented 56.6% (748/1322). 74.2% (1120/1509) of the ESFs involved the urinary system among which 79.6% (892/1120) were renal cysts. Clinically significant findings represented 8.7% (131/1509) among which hydronephrosis represented 23% (30/131). First time detected malignant lesions represented 4.6% (6/131). ESFs reporting rate was 47.3%. 58.8% of the clinically significant ESFs were not reported. ESFs prevalence was 31.1%. The Urinary system was the most commonly involved. Most ESFs were benign warranting no further workup. However, clinically significant ESF were not infrequently detected. More than half of the clinically significant findings were not reported. A systematic review of MRI images is highly recommended to improve patient’s outcome.

Febrile Urinary Tract Infections in Children with Primary Non-Refluxing Megaureter: A Systematic Review and Meta-Analysis

BACKGROUND

Knowledge of the baseline risk of febrile urinary tract infections in patients with primary non-refluxing megaureter can help clinicians to make informed decisions for offering continuous antibiotic prophylaxis.

OBJECTIVE

The primary objective of this systematic review was to determine the pooled prevalence of febrile urinary tract infections in patients with primary non-refluxing megaureter selected for primary non-surgical management independent of associated attributed risk factors at initial presentation in order to assess the value of continuous antibiotic prophylaxis.

METHODS

MEDLINE, EMBASE, and Cochrane Controlled Trials Register electronic databases were searched for eligible studies without language and time restriction. The systematic review was carried out following the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. (PROSPERO registration number CRD42018104752).

RESULTS

Of 25 871 records, 16 studies (n=749 patients) were eligible for inclusion. The overall pooled prevalence of febrile urinary tract infections in patients with primary non-refluxing megaureter was 14.35% (95% confidence interval: 8.8-22.6). The calculated number needed to treat for patients on continuous antibiotic prophylaxis to prevent one single febrile urinary tract infection over the course of 1-2 years would be 4.3.

CONCLUSION

Based on the current available evidence the use of continuous antibiotic prophylaxis for children with PM selected for primary non-surgical treatment should be taken into consideration, at least in patients with urinary outflow impairment, higher grade of ureteral dilatation, and for children in the first months of life.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Postnatal management of bilateral Grade 3-4 ureteropelvic junction obstruction

Introduction:

Bilateral hydronephrosis on prenatal ultrasound can be managed expectantly or with surgical intervention. The treatment strategies and outcomes are not clearly defined.

Methods:

We conducted a retrospectively audit of outcomes of management of prenatally detected severe bilateral ureteropelvic junction obstruction (UPJO) in our institution.Patients with bilateral Grade 3–4 hydronephrosis were included. Those with complications like rupture, underwent bilateral intervention within 4 weeks; in the remaining, unilateral pyeloplasty was performed at 4–12 weeks. The contralateral renal unit was re-evaluated at a later date for further improvement or deterioration. All the patients were followed up with ultrasonography and renogram at 3 months, 6 months, and 1-year post operatively. The case records were analyzed for the resolution of antero-posterior diameter (APD) or the improvement in single-kidney glomerular filtration rate (s-GFR) in the operated units.

Results:

Over 15 years, 28 patients (56 renal units) had bilateral UPJO (male-to-female ratio = 13:1). Twelve units underwent neonatal intervention to tackle the complications (6 bilateral pyeloplasty), 17 units underwent early pyeloplasty, and 15 underwent late pyeloplasty. Twelve of the twenty-two (54%) contralateral units, which were stented/observed, resolved spontaneously. Receiver operating characteristics analysis revealed that those with initial APD <25 mm and initial s-GFR >35 ml/m were more likely to improve during the observation. Ten of the forty-four operated units (22%) failed to show an improvement. Units with initial s-GFR <10 ml/m had poor chance of postoperative functional recovery.

Conclusions:

In neonates with bilateral UPJO, the worse affected kidney is operated first, as it still has the potential to recover. The contralateral milder UPJO unit is known to recover spontaneously following unilateral pyeloplasty. In those with bilateral Grade 4 UPJO and mass, bilateral pyeloplasty is feasible. Alternatively, unilateral pyeloplasty + contralateral cystoscopic retrograde stenting may prevent rupture or functional deterioration in the opposite kidney.

Urinary Ultrasound and Other Imaging for Ureteropelvic Junction Type Hydronephrosis (UPJHN)

Ultrasound is the main imaging study used to diagnose ureteropelvic junction (UPJ) obstruction. On ultrasound, abnormal dilatation of the pelvicalyceal system of varying degrees is seen, whereas the ureter is normal in caliber. A properly performed study provides essential information regarding laterality, renal size, thickness, and architecture of the renal cortex and degree of dilatation of the pelvicalyceal system. Doppler ultrasound may identify a crossing vessel, when present. This imaging method also has been used differentiating obstructive from non-obstructive hydronephrosis by renal arterial resistive index measurements. Abdominal radiographs may show soft tissue fullness, bulging of the flank, and displacement of bowel loops from the affected side. The voiding/micturating cystourethrogram helps exclude other causes of upper tract dilatation, including vesicoureteral reflux, urethral valves, and ureteroceles. Computerized Tomography angiography with multiplanar reformation and three-dimensional images may be used to depict suspected crossing vessels as a cause of UPJ obstruction in older children and adults. Magnetic Resonance Urography has progressed significantly in recent years due to the development of both hardware and software that are used to generate high-resolution images. This imaging technique currently allows for the detailed assessment of urinary tract anatomy, while also providing information regarding renal function, including differential renal function, and the presence or absence of obstructive uropathy.

The use of fetal MRI for renal and urogenital tract anomalies

Fetal anomalies are detected in approximately 2% of all fetuses and, among these, genitourinary tract abnormalities account for 30% to 50% of all structural anomalies present at birth. Although ultrasound remains the first line diagnostic modality, fetal MRI provides important additional structural and functional information, especially with the development of faster sequences and the use of functional sequences. The added value of MRI-based imaging is three-fold: (a) improvement of diagnostic accuracy by adequate morphological examination, (b) detection of additional anomalies, and (c) in addition, MRI has the potential to provide information regarding renal function. In this review, we describe the role of fetal MRI in the anatomical evaluation of renal and urogenital tract anomalies, and we also touch upon the contribution of functional MRI to the diagnostic workup of these conditions.

Postnatal outcomes of babies diagnosed with hydronephrosis in utero in a tertiary care centre in India over half a decade

Background

Prenatal hydronephrosis is defined as the dilatation of the fetal renal pelvis and/or calyces and is the commonest anomaly detected in utero

Methods

This was a retrospective study to look at how well 148 antenatally detected cases of fetal hydronephrosis correlated with postnatal evaluation.

Results

Antenatal hydronephrosis was detected with a prevalence of 0.33%. The mean gestational age at diagnosis was 25.48 [standard deviation (SD) 6.36]. One hundred and sixteen (78.3%) fetuses had serial ultrasound scans during pregnancy to look for the progression of the condition. At the time of diagnosis, 30.1% of the fetuses were diagnosed to have mild hydronephrosis, 43.9% to have moderate hydronephrosis and 25.8% to have severe hydronephrosis. Follow-up ultrasounds during the prenatal period, 65% showed progression of the renal pelvis dilatation, 25.8% showed stable disease and 9.1% showed resolution on their subsequent scan. Almost half (46%) were found to have transient/physiological hydronephrosis. Thirty-one (20.9%) of the babies required an operation. An anteroposterior renal pelvis diameter (APD) of the fetal renal pelvis ≥17.5 mm can predict the need for surgery with a sensitivity of 70% and a specificity of 76.6%.

Conclusion

Counselling and decisions must be based on a series of ultrasound scans rather than a single evaluation. We use a cut-off of 17.5 mm as an indicator of possible postnatal surgical intervention.

Prognostic significance of maternal urinary carbohydrate antigen 19-9 for antenatal diagnosis of posterior urethral valve associated with fetal hydronephrosis

PURPOSE

To evaluate the predictive role of maternal urinary CA 19-9 as a non-invasive marker for diagnosing antenatal posterior urethral valve (PUV).

METHODS

A total of 40 women in the third pregnancy trimester were enrolled. Case group (group A) consisted of 20 women with a diagnosis of antenatal PUV. Twenty women with similar gestational age, fetal sex, normal US, and no history of congenital anomalies were chosen as a control group (group B). Maternal urine samples were collected and urinary CA 19-9 was measured in both groups. The correlations between maternal urinary CA 19-9 and APD (measured during pregnancy and the initial evaluation of the newborn) were assessed. CA 19-9 level in first urine of neonates was also evaluated.

RESULTS

The mean ± SD of maternal urine CA 19-9 was higher in PUV group compared to the control group (131.6 ± 23.8 vs. 13 ± 2.7 U/mL). In addition, there was a significant correlation between maternal urinary CA 19-9 and the APD measured at the third trimester (p < 0.001) and the initial evaluation of fetus after birth according to SFU grading system (p < 0.001). However, no significant difference was found between gestational age and urinary CA 19-9 level (p = 0.34). There was also a significant correlation between the CA 19-9 level in first urine of neonates and CA 19-9 level of maternal urine (p < 0.001).

CONCLUSIONS

This is the first time that maternal urinary CA 19-9 has been applied as a noninvasive and practical diagnostic marker in antenatal PUV.

Applicability of Magnetic Resonance Imaging in the Assessment of Fetal Urinary Tract Malformations

OBJECTIVE

To assess the applicability of magnetic resonance imaging (MRI) to complement ultrasound in the diagnosis of fetal urinary tract anomalies.

METHODS

This was a retrospective cohort study that included 41 women between 19 weeks and 37 weeks and 6 days of gestation carrying fetuses with malformations of the urinary tract which were initially diagnosed by ultrasound and then referred for MRI. In all cases, the diagnosis was confirmed after birth either through imaging or autopsy. A surface coil was positioned over the abdomen and T2-weighted sequences were obtained in the axial, coronal, and sagittal planes; T1 in at least one plane; and three-dimensional (3-D) TRUFI in fetuses with dilatation of the urinary tract.

RESULTS

Mean gestational age at the time of MRI examination was 28.21 weeks. The rapid T2 sequences allowed all the anomalies of the fetal urinary tract to be assessed, whereas 3-D TRUFI sequencing proved very useful in evaluating anomalies involving dilatation of the urinary tract. The signs of pulmonary hypoplasia characterized by hypointense signal in the T2-weighted sequences were identified in 13 of the 41 fetuses.

CONCLUSION

MRI confirmed and added information to the ultrasound regarding fetal urinary tract anomalies, as well as information related to the other associated malformations, their progress in the prenatal period, and possible postnatal prognosis.

Comparison Characteristics of Family and Demographic of Children with Antenatal Hydronephrosis between 2nd and 3rd Trimesters of Gestation

BACKGROUND

The aim of this study was comparison characteristics of family and demographics of children with antenatal hydronephrosis, in 2^nd and 3^rd trimester of pregnancy, in order to the need for postnatal management.

METHODS

This cross-sectional study described some information from family of children with antenatal hydronephrosis, at the Pediatric Urology Research Center of Children's Hospital Medical Center of Tehran University of Medical Sciences. Data for 193 children, admitted in 2012-2013, were collected retrospectively. They were allocated to two groups of 2^nd and 3^rd trimester, based on the time of diagnosis antenatal hydronephrosis. Data analysis was done using SPSS. Chi-Square, Fisher-exact and independent t-test also Mantel-Hanzel test were used. P-value<0.05 was considered as statistically significant.

RESULTS

Of 193 infants (36 female, 157male), the antenatal hydronephrosis of 76 cases (39.4%) have been diagnosed in the 2^nd trimester. In addition, 110 cases (57%) were bilateral and 33 cases (17.1%) had severe antenatal hydronephrosis. Consanguinity marriage, being unilateral or bilateral and the severity of antenatal hydronephrosis were significant with the specific trimester that it has been diagnosed (P<0.05).

CONCLUSION

Infants with bilateral and severe grade of antenatal hydronephrosis also with the history of consanguinity marriage among their parent will diagnose in the second trimester more than the third trimester and will refer for some surgical correction, relating to other kidney diseases such as vesicoureteral reflux, more than others. Thus, this is a good sign for caring infants.

Paediatric nuclear medicine imaging

BACKGROUND

Nuclear medicine imaging explores tissue viability and function by using radiotracers that are taken up at cellular level with different mechanism. This imaging technique can also be used to assess blood flow and transit through tubular organs. Nuclear medicine imaging has been used in paediatrics for decades and this field is continuously evolving.

SOURCES OF DATA

The data presented comes from clinical experience and some milestone papers on the subject.

AREAS OF AGREEMENT

Nuclear medicine imaging is well-established in paediatric nephro-urology in the context of urinary tract infection, ante-natally diagnosed hydronephrosis and other congenital renal anomalies. Also, in paediatric oncology, I-123-meta-iodobenzyl-guanidine has a key role in the management of children with neuroblastic tumours. Bone scintigraphy is still highly valuable to localize the source of symptoms in children and adolescents with bone pain when other imaging techniques have failed. Thyroid scintigraphy in neonates with congenital hypothyroidism is the most accurate imaging technique to confirm the presence of ectopic functioning thyroid tissue.

AREAS OF CONTROVERSY

Radionuclide transit studies of the gastro-intestinal tract are potentially useful in suspected gastroparesis or small bowel or colonic dysmotility. However, until now a standardized protocol and a validated normal range have not been agreed, and more work is necessary. Research is ongoing on whether magnetic resonance imaging (MRI), with its great advantage of great anatomical detail and no ionizing radiations, can replace nuclear medicine imaging in some clinical context. On the other hand, access to MRI is often difficult in many district general hospitals and general anaesthesia is frequently required, thus adding to the complexity of the examination.

GROWING POINTS

Patients with bone pain and no cause for it demonstrated on MRI can benefit from bone scintigraphy with single photon emission tomography and low-dose computed tomography. This technique can identify areas of mechanical stress at cortical bone level, difficult to demonstrate on MRI, which can act as pain generators. Positron emission tomography (PET) is being tested in the staging, response assessment and at the end of treatment of several paediatric malignancies. PET is becoming more widely utilized in neurology in the pre-surgical assessment of some children with drug resistant epilepsy.

AREAS TIMELY FOR DEVELOPING RESEARCH

The use of PET/MRI scanners is very attractive as it combines benefits of MR imaging with the assessment of cellular viability and metabolism with PET in one examination. This imaging technique will allow important research on tumour in-vivo metabolism (possible applications include lymphomas, neuroblastomas, malignant germ cell tumours andbrain tumours), with the aim of offering a personalized biological profile of the tumour in a particular patient. Ground-breaking research is also envisaged in neurosciences, especially in epilepsy, using PET tracers that would enable a better identification of the epileptogenic focus, and in psychiatry, with the use of radiolabeled neurotransmitters. In paediatric nephro-urology, the identification of the asymptomatic child with ante-natally diagnosed hydronephrosis at risk of losing renal parenchymal function if left untreated is another area of active research involving radionuclide renography.

Controversies Regarding Management of Vesico-ureteric Reflux

The primary goal in the management of a child with urinary tract infection (UTI) is to prevent recurrence of UTI and acquired renal damage. Approximately 15% of children develop renal scarring after a first episode of febrile UTI. Vesico-ureteric reflux (VUR) is diagnosed in 30-40% of children imaged after first febrile UTI. The 'top-down' approach involving ultrasound and dimercaptosuccinic acid scan (DMSA) first after an appropriate interval following UTI, can help in avoiding voiding cystourethrogram (VCUG), an invasive test with higher radiation exposure. The majority view remains that VCUG should be done after the second attack of UTI in girls and first attack of UTI in boys. Although the evidence in favour of antibiotic prophylaxis remains doubtful in preventing renal scars associated with VUR, it remains the first line treatment for high-grade reflux (grade 3-5) with an aim to prevent UTI and allow spontaneous resolution of VUR. Early identification and appropriate treatment of associated bowel bladder dysfunction is an essential part of successful medical management of VUR. Endoscopic treatment of VUR, using a bulking agent, is useful in grade 3 VUR. The main controversy regarding intervention (endoscopic/open surgical intervention) involves absence of strong evidence for these interventions in reducing renal scarring on randomized controlled trials. However, several recent trials have found the surgical interventions to be effective in reducing recurrent pyelonephritis and repeated hospital admissions.

Variable Resource Utilization in the Prenatal and Postnatal Management of Isolated Hydronephrosis

OBJECTIVE

To characterize contemporary resource utilization and medical outcomes for infants with antenatal hydronephrosis and their mothers from a national claims database. We hypothesize that management of isolated hydronephrosis (IHN) varies widely, with decreased imaging following the 2010 Society for Fetal Urology Consensus Statement.

MATERIALS AND METHODS

Using MarketScan claims from 2007 to 2013, we identified infants 0-12 months of age with hydronephrosis and linked mothers. Those with urologic diagnoses more specific than hydronephrosis, additional urologic comorbidities, or postnatal surgeries were excluded. Resource utilization including prenatal and postnatal imaging, laboratory studies, hospital admissions, and medical outcomes within the first year was captured. Demographics, maternal characteristics, utilization measures, and outcomes were compared across imaging intensity groups based on number of postnatal ultrasounds received using bivariate analysis.

RESULTS

Among 801,919 mother-child pairs, 8610 infants (1.1%) had hydronephrosis or a related diagnosis. A total of 5876 (68.2%) met inclusion criteria for IHN. Patients underwent a mean 5.3 ± 3.5 prenatal and 2.1 ± 1.3 postnatal ultrasounds before age 1. Imaging practices were unchanged following the Society for Fetal Urology consensus statement.

CONCLUSION

Antenatal hydronephrosis prevalence in an insured population is consistent with published ranges. Prenatal imaging in IHN is variable and potentially excessive. Future study into the efficacy of evidence-based pathways in reducing excess utilization is warranted.

The role of voiding cystourethrography in asymptomatic unilateral isolated ureteropelvic junction obstruction: A retrospective study

INTRODUCTION

The presence of concomitant vesicoureteric reflux (VUR) and ureteropelvic junction obstruction (UPJO) is uncommon. Nevertheless, the reported VUR coexisting with asymptomatic unilateral isolated hydronephrosis (AUIH) requiring pyeloplasty for correction of UPJO was of low grade and mostly resolved during conservative follow-up. Therefore, VCUG may be not indicated in these children except if voiding symptoms, urinary tract infection (UTI), dilated ureters, or bladder and ureteric abnormalities are suspected.

OBJECTIVES

The aim was to evaluate the need for VCUG in infants <1 year old with AUIH for whom a dismembered pyeloplasty was indicated for correction of UPJO.

METHODS

Ninety-six children <1 year old with pyeloplasty carried out from January 2012 to March 2014 were retrospectively included. Children with voiding symptoms or dilated ureter, duplex system, fused kidneys, bilateral dilatation, or any bladder abnormality on ultrasound were excluded. Anderson-Hynes pyeloplasty was performed through a flank incision. Preoperative VCUG was analyzed in relation to outcome and any UTI during follow-up. The Student t test, Mann-Whitney U test, or Fisher exact test were used to compare variables.

RESULTS

Five children had concomitant VUR with UPJO. Most of the children were circumcised during the first postnatal week. The remaining few children were circumcised at the time of pyeloplasty. Side, grade of detected VUR, and complications (18.75%) (postoperative or during follow-up) are presented in the Table. Outcomes in children with and without VUR were not different. Dismembered pyeloplasty was successful in children with VUR and with no complications except for non-febrile UTI in one child only. Ureters were still not dilated at the last follow-up.

DISCUSSION

The required imaging in infants with AUIH is still a subject of debate. As we expected, there was a low incidence of associated VUR in the present study. They were of low grade without any complications during follow-up and without affecting the outcome. The present study has its limitations, including the retrospective nature and short follow-up. However, as at least 2 years of follow-up were documented without any harm or ureteric dilation, VUR will mostly resolve. The present study is strengthened by inclusion of infants only.

CONCLUSIONS

Our data suggest that VCUG is not indicated in infants with AUIH requiring pyeloplasty for correction of UPJO. VCUG will not affect the treatment decision, operative outcome, or postoperative complications. VCUG may be indicated in case of suspected voiding symptoms, UTI, dilated ureters, or bladder and ureteric abnormalities.

Renal development in the fetus and premature infant

Congenital abnormalities of the kidney and urinary tract (CAKUT) are one of the leading congenital defects to be identified on prenatal ultrasound. CAKUT represent a broad spectrum of abnormalities, from transient hydronephrosis to severe bilateral renal agenesis. CAKUT are a major contributor to chronic and end stage kidney disease (CKD/ESKD) in children. Prenatal imaging is useful to identify CAKUT, but will not detect all defects. Both genetic abnormalities and the fetal environment contribute to CAKUT. Monogenic gene mutations identified in human CAKUT have advanced our understanding of molecular mechanisms of renal development. Low nephron number and solitary kidneys are associated with increased risk of adult onset CKD and ESKD. Premature and low birth weight infants represent a high risk population for low nephron number. Additional research is needed to identify biomarkers and appropriate follow-up of premature and low birth weight infants into adulthood.

Determination of the Need for Surgical Intervention in Infants Diagnosed with Fetal Hydronephrosis in China

Background

Hydronephrosis is a common congenital condition. The detection of fetal hydronephrosis by ultrasound presents a treatment dilemma. This study aims to examine postnatal follow-up and treatment for hydronephrosis diagnosed prenatally.

Material/Methods

This was a retrospective study of 210 infants with hydronephrosis diagnosed at the Qilu Hospital (Shangdong, China) between January 2005 and January 2013. The patient cohort was divided into four groups based on prenatal ultrasound examinations using the Society for Fetal Urology (SFU) classification system. Data on follow-up investigations and treatment methods were extracted from the charts and analyzed.

Results

Patients with SFU grade 1, 2, and 3 hydronephrosis (n=125, n=74, and n=11, respectively) were followed for two years. In all, 2.4%, 18.9%, and 90.9% of patients with SFU grade 1, 2, and 3 hydronephrosis, respectively, underwent surgery. SFU grade 3 (HR=9.23, 95% CI: 1.43–59.74, p=0.02), APD (HR=2.81, 95% CI: 1.11–7.10, p=0.03), and parenchymal thickness (HR=0.42, 95% CI: 0.24–0.71, p=0.001) were independently associated with the occurrence of surgery. For anterioposterior diameter, using a cut-off point of 1.1, the area under the curve was 0.86, Youden index was 0.556, sensitivity was 70.4%, and specificity was 85.3%. For parenchymal thickness, using a cut-off point of 5, AUC was 0.79, Youden index was 0.478, sensitivity was 74.1%, and specificity was 73.8%.

Conclusions

Patients with SFU grade 2 hydronephrosis require long-term follow-up. Surgery and close postsurgical observation may be necessary for patients with SFU grade 3 and 4 hydronephrosis. An initial B-mode ultrasound screening at 7–10 days after birth may help make an optimal diagnosis and treatment selection.

Prenatal natural history of isolated fetal mild bilateral pyelectasis

OBJECTIVE

To analyze the prenatal outcomes in a cohort of fetuses with mild bilateral pyelectasis and determine whether performing serial ultrasounds is a good follow-up strategy.

METHODS

A prospective longitudinal study was conducted on 62 fetuses with mild bilateral pyelectasis. Fetal mild bilateral pyelectasis was considered when the renal pelvis measured (in millimeters) ≥5.0 to 10.0, ≥7.0 to 10.0, and ≥10.0 to 15 at ≤23 weeks 6 days, 24 to 31 weeks 6 days, and ≥32 weeks, respectively, with no uretero-calyceal dilatation. Ultrasounds were performed every 3 weeks to assess whether the mild bilateral pyelectasis regressed, remained unchanged (Group 1) or progressed (Group 2).

RESULTS

Group 1 consisted of 53 fetuses (85.4%), and progression was observed in 9 cases (Group 2, 14.6%). The initial renal pelvis diameter was significantly larger in fetuses with progression (p=0.028). Statistically significant differences in the renal pelvis diameter were also found at weeks 31 and 35 for both kidneys (p<0.05). The cases requiring intrauterine procedures or early delivery were not observed.

CONCLUSION

Fetal mild bilateral pyelectasis with no calyceal dilatation is a benign condition that can be managed in the postnatal period. The initial renal pelvis diameter and the diameter in week 31 or 35 were valuable parameters for identifying cases that would eventually need specific postnatal procedures.

Ultrasonography of hydronephrosis in the newborn: a practical review

Widespread use of fetal ultrasonography is accompanied by more frequent detection of antenatal hydronephrosis. Therefore, sonographic evaluation of neonates with a history of antenatal hydronephrosis is becoming more widespread. As an initial postnatal non-invasive imaging modality, ultrasonography is used to screen for persistence of hydronephrosis, determine the level and severity of obstruction, and contribute to appropriate diagnosis and treatment. This review aims to provide a practical overview of the sonographic evaluation of neonatal hydronephrosis and to describe the sonographic findings of conditions associated with hydronephrosis in the newborn.