Prospective study of outcome in antenatally diagnosed renal pelvis dilatation

10 Years of Antenatal Hydronephrosis Experience: Comparing Two Different Guidelines

BACKGROUND

Antenatal hydronephrosis refers to the dilation of the renal pelvis and/or calyces in the developing fetus. The challenge lies in distinguishing between cases that warrant long-term follow-up or surgical intervention and those with transient hydronephrosis that require minimal invasive investigations.

MATERIALS AND METHODS

Our study aimed to assess and contrast the efficacy of the 2015 Congenital Anomalies of Kidney and Urinary Tract Guideline from the Turkish Society of Pediatric Nephrology with the Tepecik Antenatal Hydronephrosis Guideline, which was previously employed in our hospital. We conducted a comparative analysis of demographic data, outcome conditions, additional imaging requirements and quantities, radiation exposures, and rates of surgical interventions between two groups.

RESULTS

Group 2 had a significantly higher detection rate of Vesicoureteral Reflux via voiding cystourethrogram at 38.5% compared to Group 1's 13.4% (p<0.01). The incidence of abnormal findings with dimercaptosuccinic acid was similar between Group 1 (28.5%) and Group 2 (26.4%) (p>0.01), but Group 2 had a higher rate of obstruction diagnosis at 68.8% versus Group 1's 29.4% (p<0.01). Group 1 had greater median radiation exposure (500 mrem vs. 200 mrem, p<0.01), and a higher proportion of patients underwent surgery (34.2% vs. 21.9%, p<0.01).

CONCLUSION

This study showed that the new guideline required fewer tests, was less invasive, and exposed patients to less radiation than the old guideline.

Radiological and surgical correlation of pelviureteric junction obstruction in positional anomalies of the kidney in children

Pelviureteric junction obstruction, also known as ureteropelvic junction obstruction, is a congenital narrowing of the urinary excretory tract at the junction between the renal pelvis and the ureter and is a common cause of congenital pelvicalyceal dilatation. The outcome is variable, from spontaneous resolution to renal parenchymal function loss in cases of untreated high-grade obstruction. Abnormalities in renal ascent, rotation and vascularity can be associated with pelviureteric junction obstruction and easily overlooked radiologically. In this pictorial review, we explore the anatomical, radiological and surgical correlations of pelviureteric junction obstruction in the context of a normal kidney and a spectrum of renal abnormalities, including hyper-rotation (also known as renal malrotation), failed renal ascent, fusion anomalies and accessory crossing renal vessels. For each scenario, we provide technical tips on how to identify the altered anatomy at the first ultrasound assessment and correlation with scintigraphic, cross-sectional and postoperative imaging where appropriate. A detailed ultrasound protocol specifically to assess and characterise pelviureteric junction obstruction in paediatric patients is also offered.

Postnatal Outcomes of Fetuses with Prenatal Diagnosis of 6-9.9 mm Pyelectasis

Pyelectasis, also known as renal pelvic dilatation or hydronephrosis, is frequently found on fetal ultrasound. This study correlated prenatally-detected, moderate pyelectasis with postnatal outcomes. This retrospective, observational study was conducted at a tertiary medical center in Israel. The study group consisted of 54 fetuses with prenatal diagnosis of pyelectasis on ultrasound scan during the second trimester, defined as anteroposterior renal pelvic diameter (APRPD) 6-9.9 mm. Long-term postnatal outcomes and renal-related sequelae were obtained using medical records and telephone-based questionnaires. The control group included 98 cases with APRPD < 6 mm. Results indicate that fetal pyelectasis 6-9.9 mm was more frequent among males (68.5%) than females (51%, p = 0.034). We did not find significant correlations between 6-9.9 mm pyelectasis and other anomalies or chromosomal/genetic disorders. Pyelectasis resolved during the pregnancy in 15/54 (27.8%) cases. There was no change in 17/54 (31.5%) and 22/54 (40.7%) progressed to hydronephrosis Among the study group, 25/54 (46.3%) were diagnosed with neonatal hydronephrosis. There were more cases of renal reflux or renal obstruction in the study group compared to the control group 8/54 (14.8%) vs. 1/98 (1.0%), respectively; p = 0.002. In conclusion, most cases of 6-9.9 mm pyelectasis remained stable or resolved spontaneously during pregnancy. There was a higher rate of postnatal renal reflux and renal obstruction in this group; however, most did not require surgical intervention.

Outcome of Patients with Antenatally Diagnosed hydronephrosis with Respect to Postnatal Diagnosis and Need for Surgical Intervention

AIMS

This study aims to determine the etiology of antenatal hydronephrosis (ANH) and predict need for surgical intervention based on antenatal renal pelvis anteroposterior diameter (APD).

MATERIALS AND METHODS

Combined prospective and retrospective study (2012-2018) of ANH cases with postnatal follow-up. Surgical intervention was correlated with the degree of hydronephrosis (HDN) and pelvis APD measured at the 2^nd trimester, 3^rd trimester, and postnatal 6-week follow-up.

RESULTS

One hundred and sixty-five patients were studied with a total of 219 ANH units. Transient HDN was seen in 116 units. Surgical intervention included pyeloplasty (n = 76), sub ureteric dextranomer injection (n = 8) and nephrectomy (n = 1). Chances of requiring surgery based on the degree of HDN in 2^nd and 3^rd trimester respectively were mild: 11.32% and 9.52%, moderate: 34.21% and 37.03% and severe: 85.71% and 86.27%. The mean increase in APD between the 2^nd and 3^rd trimester (n = 50) was lesser in conservatively managed (3.548 ± 4.219 mm) than surgically managed (8.261 ± 5.857 mm) patients (P = 0.002). In another subset (n = 37), the mean increase in APD between the 2^nd trimester and postnatal period was less in conservatively managed (1.432 ± 0.612 mm) (P = 0.088) than surgically managed patients (12.91 ± 3.247 mm) (P = 0.004). The area under the receiver operating characteristic (ROC) curve showed that an APD of 8.2 mm in the 2^nd trimester and 12.85 mm in the 3^rd trimester correlated with the requirement of postnatal surgery.

CONCLUSION

Apart from the degree of HDN, significant changes in APD between 2^nd and 3^rd trimester and cut off value suggested by the ROC curve will help during antenatal counseling with regard to requirement of postnatal surgery.

Outcome of fetuses with soft markers: results of 3016 cases in Ahvaz city

Background: Although soft markers may be seen as normal variants, they are important due to their association with chromosomal and congenital abnormalities. Methods: This cross-sectional descriptive-analytical study was done on 3016 women who referred for perinatal care. Fetuses with any of soft markers including thickened nuchal fold (TNF), mild pyelectasis (MP), choroid plexus cyst (CPC), single umbilical artery (SUA), mega cisterna magna (MCM) and mild ventriculomegaly (MVM) were followed during pregnancy and birth. Data analysis was carried out using SPSS for Windows (version 22). Data were analyzed using chi-square and T-test. A p-value <0.050 was considered statistically significant. Results: 285 (9.4%) fetuses with soft markers Including 148 (4.9%) fetuses with CPC, 118 (3.9%) fetuses with MP, 2 (0.1%,) fetuses with isolated TNF, 8 (0.3%) fetuses with isolated MVM, 4 (0.13%) fetuses with SUA, 4 (0.13%) fetuses with MCM were identified, and one fetus had TNF and MVM simultaneously. In cases with CPC, no abortion or major structural abnormalities were observed and all 148 neonates had normal phenotypes at birth. Among 118 cases with MP, one case had a major cardiac disorder, and 2 cases of abortions (1.7%) were reported (p=0.481). 83 cases (70.3%) were male and 35 cases (29.7%) were female (p=0.021) and all neonates had a normal phenotype. Both pregnancies with isolated TNF resulted in abortion. Of the 8 cases with isolated MVM, two cases had major structural abnormalities. 2 cases of abortion were reported and all infants had a normal phenotype. In one case, that fetus had TNF and MVM simultaneously. Amniocentesis showed no aneuploidy. No major structural abnormalities were observed in fetuses with SUA. One case of abortion was reported. Among the three births, two pre-term births were reported, and all three infants had normal phenotype. In four cases with MCM, no major structural abnormality was observed and all four neonates had normal phenotype. Conclusion: In cases without association with other structural abnormality, mothers who have fetuses with CPC or MP should be reassured that the pregnancy outcomes are generally favorable.

Diagnostic accuracy of an interdisciplinary tertiary center evaluation in children referred for suspected congenital anomalies of the kidney and urinary tract on fetal ultrasound - a retrospective outcome analysis

BACKGROUND

Fetal ultrasound organ screening has become a standard of care in most high-income countries. This has resulted in increased detection of congenital abnormalities, which may lead to major uncertainty and anxiety in expectant parents, even though many of them are of minor relevance. In order to optimize prenatal counselling, we introduced an interdisciplinary approach for all pregnant women referred to our center by private obstetricians for a co-assessment of suspected relevant fetal abnormalities of the kidney or urinary tract, involving both experienced prenatal ultrasound specialists and a pediatric nephrologist or urologist.

METHODS

In a retrospective analysis, we evaluated reports of intrauterine evaluation and postnatal follow-up in order to assess accuracy of explicit intrauterine diagnoses and outcome of hydronephroses according to their severity in this setting.

RESULTS

A total of 175 fetuses were examined between 2012 and 2019 and followed postnatally at our Pediatric Nephrology or Urology Department. There was a high concordance (85.9%) between explicit intrauterine and final diagnoses. Resolution rate of hydronephrosis was higher in patients with intrauterine low-grade than high-grade hydronephrosis (61.8% versus 11.9%). An etiological diagnosis was found in 62.5%, 52.0%, and 11.1% of patients with intrauterine bilateral high-grade, unilateral high-grade, and unilateral high-grade with contralateral low-grade hydronephrosis, respectively, but in none of the patients with intrauterine low-grade hydronephrosis.

CONCLUSIONS

The results of our study demonstrate that, through interdisciplinary teamwork, intrauterine assessment of the fetal kidneys and urinary tract is highly accurate and allows a good discrimination between relevant and transient/physiological hydronephroses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical Outcome of Children With Antenatally Diagnosed Hydronephrosis

Fetal renal pelvis dilation is a common condition, which is observed in 1-4. 5% of pregnancies. In many cases, this finding resolves spontaneously. However, sometimes it may be a signal of significant urinary tract pathologies. The main abnormalities found after birth are uretero-pelvic junction stenosis, primary vesicoureteral reflux, megaureter, duplex kidneys, and posterior urethral valves, with uretero-pelvic junction stenosis and primary vesicoureteral reflux accounting for most of the cases. Diagnosis, management, and prognosis at short and longer term of these conditions will be reviewed in this article.

The molecular biology of pelvi-ureteric junction obstruction

Over recent years routine ultrasound scanning has identified increasing numbers of neonates as having hydronephrosis and pelvi-ureteric junction obstruction (PUJO). This patient group presents a diagnostic and management challenge for paediatric nephrologists and urologists. In this review we consider the known molecular mechanisms underpinning PUJO and review the potential of utilising this information to develop novel therapeutics and diagnostic biomarkers to improve the care of children with this disorder.

Society for Fetal Urology Classification vs Urinary Tract Dilation Grading System for Prognostication in Prenatal Hydronephrosis: A Time to Resolution Analysis

PURPOSE

The Urinary Tract Dilation grading system for prenatal hydronephrosis was introduced to address potential shortcomings of the Society for Fetal Urology classification. Hydronephrosis resolution is an important patient outcome and is frequently discussed during family counseling. We compared these 2 grading systems and their ability to predict time to hydronephrosis resolution.

MATERIALS AND METHODS

We prospectively screened 855 patients with prenatal hydronephrosis due to ureteropelvic junction obstruction-like hydronephrosis, nonrefluxing primary megaureter or vesicoureteral reflux between 2009 and 2015. Of the patients 454 were excluded due to surgery, late referral, absence of postnatal dilatation or presence of other anomalies, resulting in 401 eligible patients (of whom 81% were male) to be included for analyses. Hydronephrosis grades collected at baseline and last followup were compared to identify resolution trends through time. Hydronephrosis resolution was defined as renal pelvis anteroposterior diameter 10 mm or less at last followup. Time to resolution was analyzed using Cox proportion regression.

RESULTS

Of 401 patients 328 (82%) had resolution during a mean ± SD followup of 24 ± 18 months (maximum 107). Cumulative resolution rate at 3 years was 98% for Society for Fetal Urology grade I hydronephrosis, 87% for grade II, 76% for grade III and 57% for grade IV. The 3-year hydronephrosis resolution rate was 90% for Urinary Tract Dilation postnatal grade 1 (low risk), 81% for grade 2 (intermediate risk) and 71% for grade 3 (high risk).

CONCLUSIONS

Patients with distinctive baseline hydronephrosis grades (classified by Society for Fetal Urology or Urinary Tract Dilation system) had significantly different resolution times for hydronephrosis (p <0.001). Counseling families regarding time to resolution of prenatal hydronephrosis should remain the same whether using Society for Fetal Urology or Urinary Tract Dilation grading system.

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.

Contemporary Management of Vesicoureteral Reflux

The past 30 years have seen broad changes in the diagnosis and management of vesicoureteral reflux (VUR). Recently, a clinical debate has generated an open discussion in academic circles. New evidence has shifted treatment patterns away from widespread surgical management and recently brought into question some pharmacologic treatments. VUR is usually not hazardous by itself but is a significant risk factor for urinary tract infection (UTI) and less commonly, renal scarring and insufficiency. Given the costs and morbidity of UTI as well as the potential for significant renal injury, our approach remains conservative. Careful follow-up, parental education about pathophysiology and management of VUR and UTI, and management of bowel and bladder dysfunction (BBD) when present, are the foundation of treatment. Additionally, though we recognize the limitation of continuous antibiotic prophylaxis (CAP), we believe the benefits outweigh the risks and costs for many patients. Careful observation can be considered in patients with a single medical home, parental understanding of what UTI signs and symptoms are, low grade VUR, no history of complicated UTIs and close follow-up. Surgical management remains a relevant option for select patients who fail conservative measures with breakthrough UTIs or failure to resolve. Minimally invasive surgical options are available with acceptable outcomes though open ureteroneocystostomy still carries the highest success rate.

Postnatal management of antenatally detected hydronephrosis

With the increasing use of ultrasonography, congenital anomalies are often picked in utero. Antenatally detected hydronephrosis is amongst the most commonly detected abnormality. The management of this condition has raised considerable debate amongst clinicians dealing with it. This article is written with an idea to provide comprehensive information regarding the postnatal management of antenatally detected hydronephrosis. A detailed review of the current literature on this topic is provided. Also, guidelines have been given to facilitate the management of this condition.

Natural history of fetal renal pyelectasis

OBJECTIVE

To follow the natural progression of fetal renal pyelectasis detected in the mid second trimester ultrasound in an unselected obstetric population.

STUDY DESIGN

Single-centered, retrospective study that included all level II ultrasounds done from Jan 2008 to Dec 2009. The initial level II ultrasound was done in the mid second trimester. The renal pyelectasis detected on the antenatal ultrasound (AUS) was classified as mild (5-7 mm), moderate (7.1-9 mm), or severe (>9.1 mm). Postnatal outcomes were classified as "Resolved", "Improving", or "Worsened".

RESULTS

Ninety-eight cases of fetal renal pyelectasis were detected. Sixteen patients were excluded. Of the remaining 82 cases of fetal pyelectasis, 32 (39%) were mild, 21 (25.6%) moderate, and 29 (35.4%) severe. In 74 (90.2%) infants, pyelectasis resolved, remained stable, or improved in the postnatal ultrasound. In eight (9.8%) infants, pyelectasis worsened.

CONCLUSION

Totally, 90.2% of pyelectasis detected on AUS resolved spontaneously, remained stable or improved. The magnitude of fetal renal pyelectasis did not correlate with postnatal outcome. All fetal renal pyelectasis ≥ 5 mm detected on the mid second trimester ultrasound should be followed antenatally. Those fetuses with persistent pyelectasis should be evaluated after birth and followed until resolution of pyelectasis or until a diagnosis is obtained.

Do infants with mild prenatal hydronephrosis benefit from screening for vesicoureteral reflux?

PURPOSE

Screening for vesicoureteral reflux in asymptomatic infants with low grade hydronephrosis is unjustified if this condition is benign. We present a cohort with prenatally detected hydronephrosis, some observed without voiding cystourethrography, and compare outcomes to a classic, screened group.

MATERIALS AND METHODS

A total of 206 consecutive children presenting with postnatally confirmed prenatally detected hydronephrosis (47% bilateral) were included in the study. Cases with associated renal or bladder anomalies were excluded. Children with low grade hydronephrosis either underwent screening voiding cystourethrography or did not, largely based on whether care was managed by a urologist or a nephrologist. Patients with high grade hydronephrosis routinely underwent voiding cystourethrography. Primary outcome was a symptomatic or febrile urinary tract infection. We used Mantel-Haenszel analysis to determine urinary tract infection risk factors during the first 2 years of life.

RESULTS

No urinary tract infection was observed in patients with grade I hydronephrosis. Urinary tract infections in low grade hydronephrosis were only seen in the voiding cystourethrogram group (7 patients), including 1 infection following voiding cystourethrogram. Urinary tract infection rate was 3.52 infections per 100 patient-years in children with low grade hydronephrosis and 11.1 infections per 100 patient-years in those with high grade hydronephrosis (p = 0.02). This increased risk of urinary tract infection in high grade hydronephrosis persisted after correcting for gender and circumcision status (IRR 3.17, p = 0.01). The association remained strong (IRR 2.48, 95% CI 0.96-6.44) but was not statistically significant (p = 0.053) after additionally correcting for vesicoureteral reflux status.

CONCLUSIONS

Our data suggest that children with low grade hydronephrosis and otherwise normal kidneys and bladder do not benefit from voiding cystourethrographic screening. Interestingly high grade hydronephrosis appears to carry a threefold greater risk of urinary tract infection compared to low grade hydronephrosis.

Fetal hydronephrosis as a predictor of neonatal urologic outcomes

OBJECTIVES

The ability to predict surgically relevant fetal renal hydronephrosis is limited. We sought to determine the most efficacious second- and third-trimester fetal renal pelvis anteroposterior diameter cutoffs to predict the need for postnatal surgery.

METHODS

We retrospectively reviewed the medical records of mothers and neonates who had a prenatal sonographic examination in our Perinatal-Pediatric Urology Clinic and received follow-up care. Hydronephrosis was defined as a renal pelvis anteroposterior diameter of 5 mm or greater in the second trimester and 7 mm or greater in the third trimester. Hydronephrosis was subdivided into mild, moderate, and severe.

RESULTS

Of 8453 fetuses, 96 met the criteria and were referred to our clinic. Isolated hydronephrosis was diagnosed in 74 fetuses, of which 53 received postnatal follow-up evaluations. The areas under the receiver operating characteristic curves for predicting postnatal surgery in the second and third trimesters were 0.770 and 0.899, respectively. The second-trimester renal anteroposterior diameter threshold that best predicted post-natal surgery was 9.5 mm (sensitivity, 71.4%; specificity, 81.1%). The third-trimester threshold that best predicted postnatal surgery was 15.0 mm (sensitivity, 85.7%; specificity, 94.6%).

CONCLUSIONS

The fetal renal anteroposterior diameter on second- and third-trimester sonography is predictive of an increased risk for neonatal urologic surgery. Surgical risk is best predicted by a third-trimester renal anteroposterior diameter threshold of 15 mm.

Clinical spectrum of antenatally detected urinary tract abnormalities with respect to hydronephrosis at postnatal ultrasound scan

AIM

The purpose of this study was to compare the outcome of infants having antenatally detected urinary tract abnormalities (AUTAs) with respect to the presence of hydronephrosis in postnatal ultrasonography (US) examination.

PATIENTS AND METHODS

Between January 1999 and October 2009, 256 infants diagnosed with AUTAs were prospectively followed. Infants were divided into two groups according to the presence of hydronephrosis in postnatal US examination: Group 1, infants with hydronephrosis; Group 2, infants without hydronephrosis (including renal cyst, agenesis, ectopic kidney). The events of interest were the presence and diagnoses of uropathy, AUTA resolution, urinary tract infection (UTI), development of renal parenchymal defects (RPDs)--focal or global scarring, dysplasia--, acute kidney injury (AKI) and chronic kidney disease (CKD), and the need for surgery and dialysis treatment.

RESULTS

The most commonly detected underlying abnormalities were ureteropelvic junction obstruction (44.8 %), vesicoureteral reflux (VUR) (30.0 %) and megaureter (9.5 %) in patients with postnatal hydronephrosis. On the other hand, multicystic dysplastic kidney (43.5 %), renal agenesis (19.4 %) and VUR (19.4 %) were mostly encountered abnormalities in patients without postnatal hydronephrosis. RPDs were significantly more common among patients with postnatal hydronephrosis compared to those without hydronephrosis (37 vs. 21 %, P = 0.02). The incidence of UTI and VUR was higher in infants with postnatal hydronephrosis than in infants without hydronephrosis. There was no statistically significant difference in terms of the development of AKI and CKD and the need for surgery and dialysis treatment between patients with hydronephrosis and those without hydronephrosis.

CONCLUSION

Infants with AUTAs should be investigated postnatally. The findings from this study will help to identify the natural history and outcome of infants with AUTAs according to the postnatal US parameters.

Renal axis deviation in urinary tract abnormalities of children: the role of renal scintigraphy

BACKGROUND

Urinary tract pathologies are common in children. Previous reports suggested a relationship between some renal pathologies and renal anatomic variations. This study evaluates the effect of different urinary tract abnormalities on scintigraphic renal long axis.

METHODS

Children referred to our nuclear medicine department for Tc-99m dimercaptosuccinic acid and/or Tc-99m N,N-ethylenedicysteine renal scintigraphies were entered consecutively. Presence of single, ectopic, or fused kidneys, extrarenal pathologies altering renal long axis, and history of renal surgery or advanced renal disease were used as exclusion criteria. If indicated, patients were assessed for vesicoureteral reflux (VUR). Long renal axis of each kidney was drawn with a line passing through the kidney's upper and lower poles using posterior image. The angle between this axis and patient's longitudinal body axis was defined as "renal angle." After defining age-groups, "age-corrected renal angle" was calculated.

RESULTS

A total of 311 cases (622 kidney units) entered the study (183 females, 128 males). Mean age was 41.8 months. Mean "renal angle" was 11.7, 11.9, 14.1, 17.6, 28.5, 16.7, and 19.2 degrees in normal, mild, moderate, and severe VUR, high-grade ureteropelvic junction (UPJ) obstruction, nonobstructive pelvic dilatation, and ureterovesical junction obstruction, respectively (P = 0.000). Applying receiver operating characteristic analysis and using ultrasonography as the gold standard, renal angle deviation of 13.75 degrees led to the sensitivity of 74.6% and specificity of 70.7% to detect pyelocalyceal system dilatation. Using a "renal angle" cutoff value of 18.7 degrees, 85% sensitivity and 85% specificity were achieved for the diagnosis of high-grade UPJ obstruction. Using "age-corrected renal angle," a cutoff value of 3.9 degrees was consistent with 60% sensitivity and 73% specificity for the diagnosis of severe VUR.

CONCLUSION

Considerable renal axis deviation is noted in patients with UPJ obstruction and severe VUR in children. Measurement of "renal angle" provides indirect but useful clues to the presence of urinary tract pathologies. Renal scintigraphy is a useful tool for drawing renal axis and measuring "renal angle," potentially making it useful for prediction of urinary tract system abnormalities.

The necessity of voiding cystourethrography in children with prenatally diagnosed hydronephrosis

The postnatal persistence of fetal hydronephrosis requires further evaluation to establish whether pathological abnormalities are present. This study determined the necessity for voiding cystourethrography (VCUG) to identify vesicoureteral reflux (VUR) in children (n = 195) with prenatally diagnosed hydronephrosis. Among the study population, the prevalence of VUR was 17.4% (24 males, 10 females). There was a poor correlation between the severity of hydronephrosis, ureteral dilatation, presence of bilateral hydronephrosis and presence of VUR. Except for the frequency of urinary tract infections and the presence of renal damage on (99m)Tc-dimercaptosuccinic acid scans, VCUG was the only reliable method for confirming VUR in this study. The diagnosis of VUR is important for the early detection of renal damage. Further information is needed to develop the optimal approach to the evaluation of prenatal hydronephrosis, with reliable parameters that avoid invasive procedures such as VCUG.

The predictive value of the first postnatal ultrasound in children with antenatal hydronephrosis

OBJECTIVE

To evaluate the effectiveness of the first postnatal ultrasound (US) in predicting the final postnatal diagnosis using a database of children followed prospectively for antenatal hydronephrosis, and to compare these findings with a systematic review of the literature.

METHODS

The study involved 1441 children who had their radiological evaluation between 3 and 60 days of life, including an US, performed at our institution in 1998-2006. Univariate and multivariate analyses were performed. A systematic review of articles on prenatal hydronephrosis resulted in 31 studies with 2202 patients who met the inclusion criteria for analysis.

RESULTS

62.0% of renal units (RUs) had transient or non-obstructive hydronephrosis. Increasing degree of hydronephrosis correlated with increased risk of urological pathologies (from 29.6% RUs in the mild group to 96.3% RUs in the severe group). A systematic review of the literature indicated very poor quality data, but the findings appeared to be concordant with those from our patient population.

CONCLUSION

The findings from this study will help to quantify the incidence of postnatal pathology based upon the first postnatal US parameters. This information is useful for counseling and for determining which postnatal radiological tests will be necessary.

[Postnatal evaluation and management of fetal pyelectasis on prenatal ultrasound]

Fetal pyelectasis is the most frequently encountered anomaly on prenatal ultrasound. The ultrasound diagnostic criteria are well established: nature of dilated structures, degree of dilatation, ultrasound appearance of the kidneys, volume of amniotic fluid. Ultrasound can also determine if the anomaly is isolated or not, which is important for the management and prognosis of the pregnancy. Ultrasound is the initial postnatal study to evaluate the urinary tract. Further management will be based on suspected diagnosis. In cases of suspected vesico-ureteral reflux, VCUG is performed. In cases of obstructive uropathy or complex malformation (duplications), MRI is performed at 6 months of age to further define the anatomy of the urinary tract. Radionuclide renogram, performed in most cases, allows evaluation of split renal function. Follow-up ultrasound is important to monitor renal development, urinary tract dilatation and appearance of the renal parenchyma. Functional follow-up is assured by radionucline renography. This comprehensive follow-up is recommended to prevent complications and progressive loss of renal function.

Significance of Postnatal Follow-up of Infants with Vesicoureteral Reflux Having Antenatal Hydronephrosis

OBJECTIVE

To evaluate the frequency of urinary tract infections (UTIs) and degree of renal parenchymal damage as well as the parameters of growth, development and nutritional status in antenatal hydronephrosis cases with vesicoureteral reflux (VUR).

METHODS

Infants, whose antenatal ultrasonography (US) showed a fetal renal pelvic diameter of 5 mm or greater were investigated. Of the 277 infants with antenatal HN, 36 [56 renal units (RUs)] were diagnosed with VUR. All cases with VUR were evaluated in terms of the frequency of UTIs, scars appearing on (99m)Technetium-dimercaptosuccinic acid scan (DMSA), growth and development [height and weight standard deviation scores (HSDS and WSDS)], and nutritional status [relative weight (RW)]. Statistical evaluation was performed using the Chi-squared test.

FINDINGS

Of these 36 patients with VUR, 25 (69.4%) were males and 11 (30.6%) females. Of the 56 RUs, 48 (85.7%) had severe VUR (≥ Grade III). The mean duration of postnatal follow-up was 37.8±24.50 months. The annual UTI frequency was found to be 1.25±0.83 episodes/year. Of these 36 infants, 32 (88.8%) recovered from VUR following either medical (17 patients, 47.2%) or surgical (15 patients, 41.6%) treatment. The initial DMSA showed parenchymal defects in 16 (44.4%) RUs, and 4 RUs showed recovery in the final DMSA. Although statistically insignificant (P>0.05), initial growth and development (HSDS: -0.17±0.86; WSDS: 0.00±0.14) and nutritional status (RW: 98.19±8.81) values gradually improved (0.05±1.06, 0.06±1.071 and 101.97±14.85, respectively).

CONCLUSION

Postnatal early diagnosis and appropriate management of VUR in infants with antenatal hydronephrosis can prevent the occurrence of frequent UTIs, renal scarring and malnutrition, enabling normal growth and development.

The Society for Fetal Urology consensus statement on the evaluation and management of antenatal hydronephrosis

The evaluation and management of fetuses/children with antenatal hydronephrosis (ANH) poses a significant dilemma for the practitioner. Which patients require evaluation, intervention or observation? Though the literature is quite extensive, it is plagued with bias and conflicting data, creating much confusion as to the optimal care of patients with ANH. In this article, we summarized the literature and proposed recommendations for the evaluation and management of ANH.

The efficacy of ultrasound and dimercaptosuccinic acid scan in predicting vesicoureteral reflux in children below the age of 2 years with their first febrile urinary tract infection

We evaluated the efficacy of dimercaptosuccinic acid (DMSA) scan and ultrasound (US) in comparison with voiding cystourethrography (VCUG) in predicting vesicoureteral reflux (VUR) in children below the age of 2 years. Medical records and radiologic studies of children (<2 years) suffering their first febrile urinary tract infection (UTI) between January 2001 and May 2007 were retrospectively reviewed. We evaluated the sensitivity, specificity, and positive and negative predictive values of US and DMSA scans in diagnosing VUR. Among 220 children with their first febrile UTI, VUR was detected in 67 (30.4%). The detection rate of VUR by US was 41.7% and 86% in the low (I, II) and high grade (III~IV) groups, respectively. Detection rate of VUR by DMSA scan was 37.5% and 88.4% in the low and high grade groups, respectively. Combining US and DMSA scan, we found that the detection rate of high grade VUR was 95.3% and that of low grade was 62.5%. During follow up, most of the low grade VURs with normal DMSA and US scans resolved or were downgraded. Most high grade VURs could be detected by US and DMSA scan, but the prediction rate was not as high in low grade VURs. However, we can anticipate spontaneous improvement without complications in patients with either low or high grade reflux and negative findings on US and DMSA scan.

Fetal pyelectasis as predictor of decreased differential renal function

PURPOSE

A decreased percent of differential function is a common indication for infant pyeloplasty but there is no recognized fetal ultrasound parameter to predict this deficit. We determined whether there is a correlation between fetal pyelectasis and the newborn percent differential function that may enhance prenatal counseling and guide postnatal evaluation.

MATERIALS AND METHODS

Our database was queried for fetal and newborn measures with fetal pyelectasis on ultrasound and the percent of differential function on renal scintigraphy. Fetal pyelectasis data were stratified by estimated gestational age and the percent of differential function. The affected cohort was defined as having 35% or less differential function and the unaffected cohort was defined as having greater than 35%. The Wilcoxon 2-sample test was used for statistical analysis with logistic regression to generate estimated probability models of a decreased percent of differential function vs mm fetal pyelectasis.

RESULTS

A total of 831 cases had fetal and newborn ultrasound data available with a total of 229 renal scans identified. Of the 229 cases 36 (16%) had 35% or less differential function on scintigraphy. At estimated gestational age 33 weeks or less the affected cohort had 8 mm greater pyelectasis than the unaffected cohort (OR 1.2, p <0.0001). At estimated gestational age greater than 33 weeks the affected cohort had 4 mm greater pyelectasis than the unaffected cohort (OR 1.07, p <0.07). Subgroup analysis before 33 weeks of estimated gestational age showed similar significance (OR >1, p <or=0.001).

CONCLUSIONS

Approximately 16% of all fetuses with pyelectasis have 35% or less differential function as newborns, including 36% identified by pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks. Fetal pyelectasis greater than 10 mm at estimated gestational age 20 to 24 weeks and greater than 16 mm at greater than 33 weeks is associated with 35% or less differential function in the newborn.

The significance of fetal renal pelvic dilatation as a predictor of postnatal outcome

OBJECTIVES

To define the clinical outcome of fetal renal pelvic dilatation (FRPD) in cohort of infants in United Arab Emirates.

STUDY DESIGN

Data were collected from all fetuses having FRPD from January 2005 to February 2008. FRPD was graded as normal (<5 mm), mild (5-9 mm), moderate (10-15 mm), and severe (>15 mm).

RESULTS

Data from 80 fetuses with 120 kidneys were studied. Nine resolved antenatally and seven were lost to follow up. Of the remaining 89 FPRD (64 patients), 36% had normal postnatal ultrasound, 22.5% significant uropathy, and 41.5% had isolated hydronephrosis. Pelvi-ureteric junction obstruction was the commonest identified underlying abnormality. Severe FRPD predicted significant postnatal uropathy with a sensitivity of 65% and a specificity of 98.6%. Moderate FRPD increased the sensitivity to 95% but decreased the specificity to 60.9%, mild FPRD was seldom (4%) associated with significant postnatal pathology. Postnatal resolution was significantly (p = 0.01) higher in mild RPD than in the moderate or severe group.

CONCLUSION

Severe FRPD need comprehensive postnatal assessment. Although moderate FRPD had a high prevalence of uropathy, they rarely needed surgical intervention. Parents could be reassured that RPD of less than 10 mm in the third trimester is unlikely to be associated with significant uropathology.

Postnatal follow-up of antenatal hydronephrosis: a health-care challenge

OBJECTIVE

To examine our experience with ANH and to determine the success of our postnatal follow-up program.

STUDY DESIGN

Charts of mothers and infants seen (2004 to 2008) at our Regional Perinatal Center were reviewed retrospectively. ANH was defined during the third trimester by anterior pelvic diameters as follows: mild 7 to 9, moderate 10 to 14 or severe >or=15 mm. Fetuses with multicystic dysplastic kidney (MCDK) were included.

RESULT

Screening of approximately 15 000 ultrasound (US) reports identified 268 fetuses with ANH. After prenatal US surveillance, 88 (33%) fetuses had resolved, while 180 (67%) required postnatal follow-up. These 180 fetuses were diagnosed with mild 38 (21%), moderate 83 (46%) and severe 19 (11%) ANH, uni or bilateral hydroureters 12 (7%), MCDK 19 (10%) and miscellaneous 9 (5%). Postnatal follow-up was successfully established for 75% of infants with hydroureters, 68% for those with MCDK and for 37% of infants with mild, 53% with moderate and 58% with severe ANH. Factors commonly known to influence compliance were not found more frequently among the 91 infants who were lost to follow-up. The only positive predictor for postnatal follow-up was a prenatal consultation with the pediatric urologist.

CONCLUSION

Our antepartum program for diagnosis of ANH is accessible and efficient; however, there was an unacceptably high number of infants lost to follow-up. The absence of traditional barriers for compliance highlights the need to explore new ways of improving postnatal follow-up of infants with ANH.

Postnatal evaluation of infants with an abnormal antenatal renal sonogram

PURPOSE OF REVIEW

Antenatally detected renal abnormalities are frequently encountered. Recommended postnatal evaluation of these infants has evolved to minimize invasive testing while maximizing detection of significant abnormalities.

RECENT FINDINGS

There is a low rate of detectable renal abnormalities in infants with a normal postnatal sonogram at 4-6 weeks of age. Routine prophylactic antibiotics are not indicated in infants with isolated antenatal hydronephrosis. Infants with a multicystic dysplastic kidney and a normal contralateral kidney on renal ultrasound do not require further evaluation. Parents of these children should be counseled on symptoms of urinary tract infections to allow prompt diagnosis.

SUMMARY

All infants with abnormalities on antenatal sonogram should undergo postnatal evaluation with a sonogram after birth and at 4-6 weeks of age. Further evaluation can be safely limited when the postnatal sonogram is normal at 6 weeks of age.

Antenatal renal pelvis dilatation: 2-year follow-up with DMSA scintigraphy

The aim of this study was to determine whether a postnatal ultrasound (US) can detect infants with antenatal renal pelvis dilatation (ARPD) who run a minimal risk of renal damage 2 years after birth. The study cohort consisted of 14,000 pregnant women who consecutively underwent routine US examinations during the second trimester. Subsequent examinations were performed on the basis of obstetrical indications. In total, 106 foetuses were diagnosed with ARPD > or =5 mm. Two postnatal US were performed on the newborns: on postpartum days 5-7 and during the third week of life. The findings were considered to be normal when the renal pelvis diameter (RPD) was < or = 7 mm and when there was no calyceal or ureteric dilatation or signs of renal dysplasia or other anomalies. Voiding cystourethrography (VCUG) was done at 6-8 weeks after birth. When the children reached 2 years of age, renal status was evaluated with DMSA scintigraphy or, if not possible, US. In 53 of the 103 children available for evaluation, the postnatal US findings were normal; 49 of the 53 children were also given a DMSA, and the results were normal in all cases. An US scan (all normal) only was performed in three children because the families refused a DMSA. One family refused any form of examination at the 2-year follow-up. Based on our results, we conclude that postnatal US can detect infants who do not require follow-up assessments of renal development.

Vesicoureteral reflux and urinary tract infection in children with a history of prenatal hydronephrosis--should voiding cystourethrography be performed in cases of postnatally persistent grade II hydronephrosis?

PURPOSE

The clinical relevance of prenatal hydronephrosis is not well-defined. We determined the risk of febrile urinary tract infection in the absence of screening for vesicoureteral reflux, and whether postnatal voiding cystourethrography should be performed in patients with a history of prenatal hydronephrosis and postnatally persistent Society for Fetal Urology grade II hydronephrosis.

MATERIALS AND METHODS

From a longitudinal database of patients with prenatal hydronephrosis maintained since 1998 we identified those with postnatally persistent grade II hydronephrosis. This cohort was divided into patients who were and were not screened with an initial voiding cystourethrogram. The rates of vesicoureteral reflux and development of febrile urinary tract infection were determined.

RESULTS

Of 2,076 patients with prenatal hydronephrosis 1,514 had grade II hydronephrosis. Of the patients 76% underwent an initial voiding cystourethrogram and vesicoureteral reflux was found in 28%. There was no relation between laterality of hydronephrosis and incidence of vesicoureteral reflux. There was no difference between nonscreened and screened patients with respect to gender and laterality of hydronephrosis. Urinary tract infection developed in 1.3% of the patients who were screened and did not have vesicoureteral reflux and, therefore, were not receiving antibiotics. Of the screened patients with vesicoureteral reflux who were receiving prophylactic antibiotics urinary tract infection developed in 1.6% at a mean age of 9.4 months. In 363 patients who did not undergo an initial voiding cystourethrogram we estimated (based on the screened population) that 101 would have vesicoureteral reflux and 5 would have a urinary tract infection. However, a febrile urinary tract infection developed in 16 patients (4.4% overall, p <0.0001) at a mean age of 9.3 months. Voiding cystourethrogram performed in these 16 patients revealed vesicoureteral reflux in 12. Of all the patients with a urinary tract infection who were ultimately observed to have vesicoureteral reflux (including those initially screened and those discovered to have reflux after a urinary tract infection) the laterality of hydronephrosis, grade of reflux and laterality of reflux were comparable.

CONCLUSIONS

In patients with a history of prenatal hydronephrosis who are observed to have postnatally persistent grade II hydronephrosis identification of vesicoureteral reflux and use of prophylactic antibiotics significantly reduce the risk of febrile urinary tract infection. Therefore, we recommend that patients with a history of prenatal hydronephrosis and postnatally persistent hydronephrosis be screened with voiding cystourethrography early in life, and be placed on prophylactic antibiotics until the screening results are known.

Mild fetal renal pelvis dilatation: much ado about nothing?

BACKGROUND

Renal pelvis dilatation (RPD) occurs in 1% of fetuses. Severe RPD (>15 mm) is frequently associated with urinary tract pathology. For the majority with mild (5 to 9 mm) to moderate (10 to 15 mm) RPD, however, there is uncertainty about the risk of abnormalities and how much postnatal investigation is required.

STUDY DESIGN

Systematic review of cohort studies of fetuses with RPD < or = 15 mm and metaregression to estimate risks of postnatal RPD, obstruction, and VUR.

RESULTS

Of 506 potentially relevant papers, 18 met the inclusion criteria. Risk of postnatal RPD increased with fetal RP size and earlier gestation. Odds ratios for postnatal RPD doubled per millimeter increase in fetal RP size: At 20 wk gestation, for example, 18% of fetuses with mean RP of 6 mm were estimated to have persistent postnatal RPD, compared with 95% of fetuses with 12 mm RPD, but risks were decreased by 16% to 18% per week of presentation gestation. Estimated risks of obstruction and VUR were substantially lower, particularly in the mild group such as the 6 mm example above: obstruction 2%, VUR 4%.

CONCLUSIONS

Our novel risk estimates are useful for antenatal counseling at presentation. The low frequency of obstruction/VUR in mild RPD raises questions over the most appropriate investigation of these cases but further data are required before establishing definitive postnatal management pathways. We suggest the need for a large prospective multicenter study to collect individual patient parameters/results and search for additional prognostic indicators.

Postnatal investigation of fetal renal disease

Following the introduction of routine prenatal scanning, and more recently detailed anomaly scans, antenatal ultrasound (US) diagnosis of fetal renal tract abnormalities has become well established. Prenatal detection has resulted in a group of asymptomatic infants becoming patients in the last two decades. These infants are referred for paediatric (general, urological and nephrological) consultations, radiological imaging and monitoring. The urgency with which to undertake imaging depends on the suspected antenatal diagnosis and clinical scenario, with bilateral hydronephrosis, posterior urethral valves and complicated duplex systems taking a high priority. Treatment is mainly preventive and relies on close follow-up and timely intervention. US remains the main imaging modality of choice postnatally; together with nuclear medicine, it gives a powerful combination of both anatomy and function. However, magnetic resonance urography may have increasing importance in becoming the investigation of choice of the future for more complex cases.

The long-term outcome of antenatal hydronephrosis up to 15 millimetres justifies a noninvasive postnatal follow-up

AIM

To assess the incidence of urinary tract infections (UTIs) and surgery in infants with different grades of antenatal hydronephrosis (ANH) and to evaluate incidence, severity and course of underlying vesicoureteral reflux (VUR).

METHODS

Retrospective data of 125 infants with ANH were collected. The patients were divided into two groups according to the anterior-posterior pelvis diameter: group I, 5-14 mm and group II, > or =15 mm.

RESULTS

UTIs developed in 4 of 106 infants from group I and 5 of 19 infants from group II. Surgical interventions were performed on 1 of 106 patients of group I and 7 of 19 patients of group II. These differences were statistically significant (p-values 0.004 and <0.001, respectively). In group I, 6 of 106 patients had VUR; none of them required surgical intervention and only two developed a UTI (one of whom also had contralateral ureteropelvic junction obstruction). Five of 19 infants in group II had underlying VUR, four of them with associated anomalies, 1 infant required surgical correction and 4 developed UTIs.

CONCLUSION

Infants with ANH up to 15 mm have a low incidence of UTIs and surgery and a low incidence and benign course of underlying VUR. Therefore, noninvasive postnatal follow-up is justified and standard voiding cystourethrography should not be performed, but only in cases of ureteric dilatation.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

Urinary tract infection in the newborn: clinical and radio imaging studies

The objective of this study was to assess clinical characteristics and results of radio imaging studies and compare community-acquired urinary tract infection (UTI) with nosocomial UTI in 301 neonates with UTI consecutively admitted to 28 neonatal units in Spain over 3 years (community-acquired UTI, n = 250; nosocomial UTI, n = 51). UTI was diagnosed in the presence of symptoms of infection together with any colony growth for a single pathogen from urine obtained by suprapubic aspiration, or >or=10(4) CFU/ml for a single pathogen from urine obtained by urethral catheterization. Abnormal renal ultrasound was present in 37.1% of cases (34% in community-acquired UTI and 54.5% in nosocomial UTI, P < 0.01). The voiding cystourethrography (VCUG) showed vesicoureteral reflux (VUR) in 27% of cases (23.8% in community-acquired UTI and 48.6% in nosocomial UTI, P < 0.01). In patients with abnormal renal ultrasound and VUR, renal scan with dimercaptosuccinic acid (DMSA) performed early after UTI revealed cortical defects in 69.5% of cases. However, in patients with abnormal renal ultrasound and normal VCUG, DMSA also revealed cortical defects in 39% of cases. The absence of VUR in neonates with UTI and abnormal renal ultrasound does not exclude the presence of cortical defects suggestive of pyelonephritis.

Antenatally detected hydronephrosis

The strategy of management of children with hydronephrosis has considerably changed as a result of the development of ultrasound techniques, allowing a prenatal detection. Hydronephrosis is defined as a dilation of the renal collecting system, and several entirely different clinical entities can be considered this general heading, whereas early detection may have a different impact depending on the entity considered. The present work aims to describe a certain number of these clinical entities, to discuss the strategic options of management that are proposed, and to evaluate the role of medical imaging, in particular the radionuclide approach. Congenital ureteropelvic junction anomaly, vesicoureteral reflux, posterior urethral valves, and duplex kidney will be successively considered. Multicystic dysplastic kidney disease, although not classified as hydronephrosis, will be mentioned because it may be mistaken for hydronephrosis.

Postnatal management of isolated mild pelvic dilatation detected in antenatal period

AIM

Mild antenatal renal pelvic dilatation (ARPD) revealed by prenatal ultrasound (US) raises the question whether or not screening for vesicoureteral reflux (VUR) is mandatory. The aim of our study was to suggest guidelines for postnatal management of infants with mild ARPD defined as an antero-posterior (AP) dilatation >5 and <10 mm.

METHOD

Therefore we assessed the value of postnatal US at day 30 to predict VUR, the incidence of VUR at day 30 and the rate of spontaneous resolution at 1 year. Two hundred (200) infants with ARPD were included and had renal US and voiding cystourethrography (VCUG) at day 30. If VUR was present, VCUG was repeated 1 year later.

RESULTS

Incidence of VUR was 10% (20/200) at day 30 after birth and only 3% (6/200) 1 year later. VUR at day 30 was twice as frequent in children with postnatal dilatation (11%) than in nondilated kidneys (6%).

CONCLUSIONS

Considering the low incidence of VUR at 1 year, screening for VUR in mild ARDP seems not to be justified. However follow-up by US to detect increase in dilatation and clinical monitoring for signs of urinary infection is required.

Micturating cystourethrograms are not necessary for all cases of antenatally diagnosed hydronephrosis

OBJECTIVE

Since 1995 we have, at our centre, adopted a selective approach to performing micturating cystourethrograms (MCUGs) on patients with antenatally diagnosed hydronephrosis. This study reviews the outcome of this policy.

METHODS

We carry out MCUGs only if any of the following features are present on ultrasound: bilateral hydronephrosis, ureteric dilatation, renal scarring, bladder wall thickness greater than 5mm, or presence of a duplex system or ureterocele. Patients with simple unilateral hydronephrosis are excluded, and are managed with 6 months' trimethoprim prophylaxis and ultrasound surveillance with a minimum of 3 years' follow up.

RESULTS

Fifty-five patients were referred with an antenatal diagnosis of hydronephrosis between 1999 and 2002; 26 (47%) did not have an MCUG. Of these, five had increasing hydronephrosis and required surgery for pelvi-ureteric junction obstruction, and three had a multicystic dysplastic kidney on postnatal scanning. In the remaining 18 patients, the hydronephrosis resolved spontaneously, with no renal scars or asymmetry. During follow up, none of these patients had a urinary tract infection.

CONCLUSION

We believe that vesico-ureteric reflux in most antenatally diagnosed hydronephrotic kidneys is physiological rather than pathological, and resolves with time without causing long-term renal damage. This is a separate entity from, rather than a precursor of, the pathological symptomatic refluxing kidney in older, mainly female children. Taking a more conservative approach to the postnatal investigation of antenatally diagnosed hydronephrotic kidneys has not resulted in any missed damaged kidneys, but has reduced the number of invasive investigations performed. A careful protocol and detailed postnatal ultrasonography are important to prevent missed pathological cases.

Mild pyelectasis diagnosed by prenatal ultrasound is not a predictor of urinary tract morbidity in childhood

OBJECTIVES

To determine whether children with prenatally diagnosed mild pyelectasis have more urinary tract morbidity during childhood than children without this finding.

METHODS

Case-control study in children with pyelectasis (anteroposterior diameter of the fetal renal pelvis of 5-10 mm). A validated questionnaire was sent to the parents of 208 cases and 416 matched controls.

RESULTS

The questionnaire was returned by 146 cases and 250 controls. There was a male predominance in the case group (p = < 0.0001). There was no difference in voiding habits or in prevalence of urinary tract infections (UTI). The prevalence of UTI was high: 11.6% in cases and 10.0% in controls. The only difference was a higher prevalence of constipation in the case group (p = 0.003). Postnatally, 41 children had an ultrasound examination and 16 were referred to a paediatrician or urologist: 3 had persisting pyelectasis, 3 had a recurrent UTI and 1 required surgery (a pyeloplasty). Four of the controls were referred to a paediatrician or urologist: 3 had recurrent UTI and 1 had urinary incontinence.

CONCLUSION

Children with a mild fetal pyelectasis do not have more urinary tract morbidity during childhood than children without this finding. Therefore, there seems to be no need for additional investigation after birth.

Vesico-ureteral reflux in children with prenatally detected hydronephrosis: a systematic review

OBJECTIVE

To investigate the value of prenatally detected hydronephrosis (PNH) as a prognostic factor for vesico-ureteral reflux (VUR).

METHODS

The MEDLINE database was searched for articles on PNH and VUR published between 1980 and 2004. A total of 18 studies were identified and reviewed for various aspects. Results were separated for primary and/or secondary VUR whenever possible, because of the different underlying pathogenic mechanisms.

RESULTS

There was considerable variation between the different studies with respect to methodology and study design. One of the main discrepancies was the way in which postnatal abnormalities were ascertained: by postnatal ultrasound, voiding cystourethrogram (VCUG) alone, or combined or sequential ultrasound and VCUG. Taking these limitations into account, the published data showed there to be a mean prevalence of 15% for postnatal primary VUR after PNH. Of all patients with PNH, 53% had no postnatal anomalies, whereas 29% had other anomalies, such as duplex collecting systems.

CONCLUSIONS

Of all infants with PNH, 15% had primary VUR proven postnatally and 53% had no other anomalies detected. We suggest a standardized protocol for future studies, to enable better comparison of follow-up protocols. Published by John Wiley & Sons, Ltd.

Antenatal renal pelvic dilatation; the long-term outlook

AIM

The purpose of this study was twofold: first to provide data for more accurate counselling of parents with regard to prognosis, and second, to ensure that by following a policy of selective micturating cystourethography (MCUG), significant pathology is not missed, in particular vesicoureteric reflux (VUR). (MCUG is only undertaken if the renal pelvic diameter (RPD) is >/= 10 mm or if there is calyceal or ureteric dilatation.)

MATERIAL AND METHODS

Data were collected prospectively over a 6-year period. Pre and postnatal imaging findings were collected for all infants in whom a RPD of >/= 5 mm was identified at any gestational age. The imaging records of all patients were reviewed in 2005 for evidence of pathology detected after re-presentation with symptoms. The age range at review varied from 2-8 years.

RESULTS

Complete data were available in 527 infants. The risk of significant pathology was related to the degree of antenatal renal pelvic dilatation varying from 6% for a RPD of 5 mm at 20 weeks gestation to 38% at 10 mm. At 28-33 weeks gestation the risk varied from 5% at 5mm to 15% at 10 mm. Subsequent imaging record review revealed only one patient with grade II VUR in the study population not picked up by our selective MCUG policy.

CONCLUSION

The present study provides prognostic information that can be given to parents both antenatally and postnatally, and reassurance that a selective MCUG policy is appropriate.

Is screening for vesicoureteral reflux mandatory in infants with antenatal renal pelvis dilatation?

AIM

To determine whether postnatal ultrasound (US) can guide the use of voiding cystourethrography (VCUG) in infants with antenatally detected renal pelvis dilatation (ARPD).

METHODS

14,000 pregnant women consecutively underwent routine US examination during the second trimester. US examinations later in pregnancy were performed as follow-up of previous anomalies or on obstetrical indications. One hundred and six fetuses with ARPD > or =5 mm were identified. Two postnatal US examinations were performed in the newborns: on the 5th to 7th day and during the 3rd week of life. The findings were considered normal when renal pelvis dilatation (RPD) was < or =7 mm on both US examinations, and no calyceal or ureteric dilatation or signs of renal dysplasia or other anomalies were present. VCUG was done 6 to 8 wk after birth.

RESULTS

In 53 of 103 analysable infants, the postnatal ultrasonographic findings were normal. The VCUG was abnormal in three of these 53 infants, all with vesicoureteral reflux (VUR) grade I. Of 50 infants who had abnormal US examinations, six had VUR, four of which were grade IV and V reflux.

CONCLUSION

In infants with ARPD who undergo two postnatal US examinations with RPD < or =7 mm and have no other abnormalities, VCUG is unnecessary.

Applying the ALARA concept to the evaluation of vesicoureteric reflux

The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux.

Antenatal hydronephrosis as a predictor of postnatal outcome: a meta-analysis

OBJECTIVE

Antenatal hydronephrosis is diagnosed in 1% to 5% of all pregnancies; however, the antenatal and postnatal management of hydronephrosis varies widely. No previous studies define the risk of postnatal pathology in infants with antenatal hydronephrosis. Our objective was to review the current literature to determine whether the degree of antenatal hydronephrosis and related antenatal ultrasound findings are associated with postnatal outcome.

METHODS

We searched Medline (1966-2005), Embase (1991-2004), and the Cochrane Library databases for articles on antenatal hydronephrosis. We required studies to have subjects selected on the basis of documented measurements of antenatal hydronephrosis and followed to a postnatal diagnosis. We excluded case reports, review articles, and editorials. Two independent investigators extracted data.

RESULTS

We screened 1645 citations, of which 17 studies met inclusion criteria. We created a data set of 1308 subjects. The risk of any postnatal pathology per degree of antenatal hydronephrosis was 11.9% for mild, 45.1% for moderate, and 88.3% for severe. There was a significant increase in risk per increasing degree of hydronephrosis. The risk of vesicoureteral reflux was similar for all degrees of antenatal hydronephrosis.

CONCLUSIONS

The findings of this meta-analysis can potentially be used for prenatal counseling and may alter current postnatal management of children with antenatal hydronephrosis. Overall, children with any degree of antenatal hydronephrosis are at greater risk of postnatal pathology as compared with the normal population. Moderate and severe antenatal hydronephrosis have a significant risk of postnatal pathology, indicating that comprehensive postnatal diagnostic management should be performed. Mild antenatal hydronephrosis may carry a risk for postnatal pathology, but additional prospective studies are needed to determine the optimal management of these children. A well-defined prospective analysis is needed to further define the risk of pathology and the appropriate management protocols.