Postnatal management of infants with antenatally detected hydronephrosis

The effect of urinary diversion on kidney function in posterior urethral valves and ureterovesical obstruction

INTRODUCTION

Posterior urethral valves (PUV) and ureterovesical junction obstruction (UVJO) are common etiologies of lower urinary tract obstruction. The primary objective of therapy is to alleviate the obstruction in the urinary system. Temporary urinary diversion may be necessary in certain situations, such as Urinary tract infection (UTI), sepsis, and unchanging hydronephrosis. This study, aims to assess kidney parameters after urinary diversion (either pyelostomy or ureterostomy) in patients with PUV and UVJO.

METHOD

We conducted a retrospective analysis of all patients diagnosed with PUV or UVJO and treated with urinary diversion following urinary undiversion at our facility between 2015 and 2020. The following variables were collected: demographic details, surgical interventions (type of diversion), serum creatinine throughout follow-up, anterior-posterior diameter of the pelvis (APP), anterior-posterior diameter of the ureter (APU), and sonographic findings of renal parenchymal thickness (PT) as documented by a pediatric radiologist. Additionally, before and after urinary diversion, a Dimercapto succinic acid (DMSA) nuclear renal scan was conducted to assess renal function.

RESULT

We analyzed 67 patients, with a mean follow-up of 38.3 months, undergoing either ureterostomy (42 patients) or pyelostomy (25 patients). This included 38 patients with PUV and 29 with UVJO. In PUV patients, significant improvements were observed in APP (MD = 5.56 ± 11.6, p = 0.0194), APU (MD = 5.57 ± 7.28, p < 0.001), and PT (MD = 3.66 ± 2.75, p < 0.001). Similarly, UVJO patients experienced significant improvements in APP (MD = 12.18 ± 18.63, p = 0.005), APU (MD = 7.82 ± 8.98, p = 0.001), and PT (MD = 2.79 ± 3.33, p = 0.001). DMSA scores did not significantly change in either group (p > 0.05). Notably, APP improved more in UVJO patients compared to PUV patients (p = 0.047).

CONCLUSION

Our study suggests that urinary diversion could improve APP, APU, and renal parenchymal thickness in PUV and UVJO patients. The improvement of APP in UVJO patients was greater than in the PUV group. We propose further multi-center studies with longer durations of follow-up and more detailed additional data to support and confirm our results.

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.

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

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

CONCLUSION

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

WHAT IS KNOWN

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

WHAT IS NEW

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

Antenatally detected urinary tract dilatation: long-term outcome

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

Outcomes of intermediate-risk hydronephrosis in pediatric patients

PURPOSE

Hydronephrosis is a common antenatal diagnosis and is present in approximately 1-5% of pregnancies. The urinary tract dilation (UTD) classification system was introduced in 2014 and stratifies post-natal hydronephrosis risk into three groups: low-risk (P1), intermediate-risk (P2), and high-risk (P3). Recommendations for P3 hydronephrosis have been established, whereas those for P1 and P2 UTD are often left to the discretion of providers with P1 considered low-grade and less concerning significant pathology. Given the obscure nature of P2 hydronephrosis, we sought to determine the natural history and outcomes of pediatric patients with P2 hydronephrosis within a single institution.

MATERIALS AND METHODS

Children <18 years old diagnosed with hydronephrosis between January 2015 and December 2018 were identified by ICD-9 and ICD-10 codes. Patients with P1 hydronephrosis, P3 hydronephrosis, known vesicoureteral reflux, complex anomalies (ex. Posterior urethral valve), neurological impairments, neurogenic bladder secondary to spinal abnormalities, and <6 months of follow-up were excluded. The development of urinary tract infection (UTI; ≥100 000 CFU/mL of bacterial growth, UA > 10 WBCs/hpf with fever >38C), need for surgical intervention (impaired renal function, worsening hydronephrosis, and/or delayed drainage on diuretic renography), and stability of hydronephrosis were collected retrospectively.

RESULTS

Eighty-seven patients [105 renal units (RU)] were included. Twenty-six patients (30%) were female and 61 (70%) were male. Of the male patients, 30 (49%) of them were circumcised. The median age at initial evaluation was 1 month, and the median duration of follow-up was 13 months. Thirty-four (32%) RU had complete resolution, 24 (23%) improved to P1 hydronephrosis, 33 (31%) remained stable, and 14 (13%) progressed to P3 hydronephrosis. The median duration to resolution and improvement was 8.5 months and 5 months, respectively. Eleven (11%) RU required surgical intervention, 10 of which underwent pyeloplasty, with a median duration to intervention of 9 months. Fifty-five patients (63%) received antibiotic prophylaxis (amoxicillin or sulfamethoxazole-trimethoprim) for a median duration of 5 months. Nine patients (10%) developed a UTI, 3 of which were taking antibiotic prophylaxis at the time of infection.

CONCLUSIONS

Intermediate-risk hydronephrosis diagnosed in the pediatric population will either improve, resolve, or remain stable during 1-year follow-up in 87% of RU. Only 11% of RU required surgical intervention, and 19% of patients developed a UTI in the absence of antibiotic prophylaxis. These findings will assist with counseling parents concerning the importance of follow-up imaging and monitoring for UTI. However, the low risk of surgical intervention is encouraging and should be discussed with the children's caretakers.

Reliability of Sonography for the Prediction of Vesicoureteral Reflux in Children With Mild Hydronephrosis

Objectives:

Postnatal evaluation of vesicoureteral reflux (VUR) remains controversial in patients with antenatal hydronephrosis (HN). The objective of this study was to identify the significance of mild postnatal HN as a marker of VUR and its severity.

Materials and Methods:

Sonographic findings of 248 children (351 kidneys) with persistent postnatal HN were evaluated for the incidence and severity of primary VUR.

Results:

The majority of patients had mild (67.8%) HN, followed by moderate (27.6%) and severe (4.6%) HN. VUR was identified in 14.7% of patients with mild HN, 18.5% of patients with moderate HN, and 18.7% of patients with severe HN. About 11.44% of patients with mild HN had low-grade VUR, followed by moderate (45.71 %) and severe grades (42.85%).

Conclusion:

A large number (89%) of patients with mild HN had moderate to severe VUR. In this cohort, renal sonography was not a reliable method for the prediction of VUR and its severity in patients with mild postnatal HN. However, it was reliable for high grades of VUR. These results are limited due to the study design and the inability to generalize these findings. These results should be replicated across other multiple clinics, thereby recruiting more variety of patients, to validate these study recommendations.

Postnatal management of children with antenatal hydronephrosis

Background

Postnatal management of infants with antenatal hydronephrosis (ANH) is still one of the most controversial issues. The majority of infants with ANH are asymptomatic with only few children who develop renal insufficiency. Thus, the biggest challenge for pediatric urologists is to distinguish children who will require further investigations and possible intervention prior to the development of symptoms, complications or renal damage in a cost effective manner without exposing them to the hazards of unnecessary investigations.

Main body

In this review article, literature on ANH were reviewed to present the current suggestions, recommendations, guidelines and their rational for postnatal management of ANH. It is agreed that a large portion of infants with ANH will improve; thus, the protocol of management is based mainly on observation and follow-up by ultrasound to detect either resolution, stabilization or worsening of hydronephrosis. The first 2 years of life are critical for this follow-up as the final picture is mostly reached during that period. Advanced imaging using voiding cystourethrography or renal scintigraphy are required for children at risk. Then, surgical intervention is selected only for a subgroup of these infants who showed worsening of hydronephrosis or renal function.

Conclusions

The protocol of management is based mainly on observation and follow-up by US to detect either resolution, stabilization or worsening of hydronephrosis. Postnatal evaluation should be performed for any neonate with a history ANH at any stage during pregnancy even if it was resolved during third trimester. Exclusion of UTI should be performed by urinalysis for all cases followed by urine culture if indicated. Serum creatinine should be performed especially in patients with bilateral ANH. US is the initial standard diagnostic imaging technique. Other imaging modalities like VCUG and nuclear renal scans may be required according to the results of the US evaluation. The most important items in decision making are the presence of bilateral or unilateral hydronephrosis, presence or absence of hydroureter, presence of lower urinary tract obstruction and degree of hydronephrosis on the initial postnatal US. Then an intervention is selected only for a subgroup of these patients who showed deterioration in renal function or degree of hydronephrosis or were complicated by UTIs. All these recommendations are based on the available literature. However, management of ANH is still a controversial issue due to lack of high evidence-based recommendations. Randomised controlled studies are still needed to provide a high level evidence for different aspects of management.

Management of antenatal hydronephrosis

Antenatal hydronephrosis (AHN) is the most frequently detected abnormality by prenatal ultrasonography. Differential diagnosis of AHN includes a wide variety of congenital abnormalities of the kidney and urinary tract ranging from mild abnormalities such as transient or isolated AHN to more important ones as high-grade congenital vesicoureteral reflux or ureteropelvic junction obstruction. It is well known that the outcome depends on the underlying etiology. Various grading systems have been proposed for the classification of AHN on prenatal and postnatal ultrasonography. Mild isolated AHN represents up to 80% of cases, is considered to be benign, and majority of them resolve, stabilize, or improve during follow-up. Controversies exist regarding the diagnosis and management of some important and severe causes of AHN such as high-grade vesicoureteral reflux and ureteropelvic junction obstruction. Current approach is becoming increasingly conservative during diagnosis and follow-up of these patients with less imaging and close follow-up. However, there is still no consensus regarding the clinical significance, postnatal evaluation, and management of infants with AHN. The aim of this review is to discuss the controversies and provide an overview on the management of AHN.

ACR Appropriateness Criteria® Antenatal Hydronephrosis-Infant

Antenatal hydronephrosis is the most frequent urinary tract anomaly detected on prenatal ultrasonography. It occurs approximately twice as often in males as in females. Most antenatal hydronephrosis is transient with little long-term significance, and few children with antenatal hydronephrosis will have significant obstruction, develop symptoms or complications, and require surgery. Some children will be diagnosed with more serious conditions, such as posterior urethral valves. Early detection of obstructive uropathy is necessary to mitigate the potential morbidity from loss of renal function. Imaging is an integral part of screening, diagnosis, and monitoring of children with antenatal hydronephrosis. Optimal timing and appropriate use of imaging can reduce the incidence of late diagnoses and prevent renal scarring and other complications. In general, follow-up neonatal ultrasound is recommended for all cases of antenatal hydronephrosis, while further imaging, including voiding cystourethrography and nuclear scintigraphy, is recommended for moderate or severe cases, or when renal parenchymal or bladder wall abnormalities are suspected. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Prenatal Urinary Tract Dilatation

Urinary tract dilatation (UTD) is the most common congenital anomaly detected on prenatal ultrasonography (US), affecting 1% to 3% of all pregnancies. This article focuses on the prenatal detection of UTD and the postnatal evaluation and management based on the UTD grading system risk assessment. Prophylactic antibiotics and postnatal imaging are discussed. The recent management trend is for a more conservative approach to minimize unnecessary testing and exposures to the fetus and neonate while detecting those who may have clinically significant disorder. The renal bladder US remains a critical part of the evaluation and helps guide further investigations.

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.

Determination of threshold value for follow-up of isolated antenatal hydronephrosis detected in the second trimester

INTRODUCTION

Isolated antenatal hydronephrosis (ANH), defined as a dilation of the renal pelvis (≥5 mm), is one of the most common abnormalities detected on prenatal ultrasound. However, established cut-off values for postnatal follow-up differ between countries and are based on little evidence. The current protocol in the Netherlands for follow-up might be too conservative.

OBJECTIVE

To assess the applicability of a higher threshold for follow-up of isolated antenatal hydronephrosis (ANH) than the current practice, without the risk of missing significant postnatal urinary tract obstruction.

STUDY DESIGN

Retrospective case series on all fetuses with isolated ANH (anteroposterior pelvic diameter (APPD) ≥5 mm) at the second trimester anomaly scan, and diagnosed between 2000 and 2009, in relationship to renal outcome.

RESULTS

A total of 279 infants with second trimester isolated ANH were included. In 201/279 (72%) fetuses, ANH had normalized (APPD <10 mm) before the third trimester scans. Hydronephrosis persisted postnatally in a minority of 56/279 (20.1%). Postnatal assessment showed signs of obstruction in 41/279 (14.7%) infants, duplicated collecting system or vesicoureteral reflux (VUR). Surgery was performed in 18/279 (6.5%) infants. A non-functioning kidney was shown in 6/279 (2.2%) infants with ANH. Mild ANH (APPD <7 mm) during the second trimester (172/279 (61.6%)) never resulted in surgery for renal anomalies or non-functioning kidney. Infants with an APPD ≥10 mm in the second trimester were far more likely to develop renal anomalies or undergo surgery compared with infants with an APPD 7-10 mm. The number of non-functioning kidneys was too low to be conclusive.

CONCLUSIONS

Follow-up ultrasounds for isolated ANH ≥7 mm instead of ≥5 mm at the second trimester scan would have saved 62% of third trimester scans, without missing any infant with a non-functioning kidney, significant obstruction or symptomatic VUR. In view of the results, it is reasonable that referral for follow-up of second trimester ANH is not strictly indicated in cases with an APPD <7 mm.

Ureteropelvic Junction Obstruction and Parathyroid Adenoma: Coincidence or Link?

Congenital ureteropelvic junction obstruction (UPJO) is the most common cause of upper urinary tract obstruction in children. It is generally diagnosed in the routine work-up during antenatal period and is characterized by spontaneous recovery. It can be associated with urolithiasis; hence further investigation should be carried out. We report the case of a 15-year-old boy, who is known to have right UPJO, presented with right renal colic and discovered to have bilateral kidney stones. Further studies showed primary hyperparathyroidism and genetic analysis revealed a CDC73 mutation (initially HRPT2). We believe that association of UPJO and PHPT is a rare coincidence that can be linked. Careful work-up of children with UPJO and urolithiasis is recommended to exclude an underlying metabolic disease. Surgical correction can be evitable as treatment of the primary cause can lead to complete dissolution of kidney stones and improvement of the medical condition.

Follow-up imaging after pediatric pyeloplasty

Introduction:

The duration, methods and frequency of radiographic follow-up after pediatric pyeloplasty is not well-defined. We prospectively evaluated a cohort of children undergoing pyeloplasty to determine the method for follow-up.

Methods:

Between 2000 and 2008, children undergoing pyeloplasty for unilateral ureteropelvic junction obstruction were evaluated for this study. All patients were evaluated preoperatively with protocol ultrasound (USG) and diuretic renal scan (RS). On the basis of preoperative split renal function (SRF), these patients were divided into four groups – Group I: SRF > 40%, Group II: SRF 30–39%, Group III: SRF 20–29%, and Group IV: SRF 10–19%. In follow-up, USG and RS were done at 3 months and repeated at 6 months, 1 year, and then yearly after surgery for a minimum period of 5 years. Improvement, stability, or worsening of hydronephrosis was based on the changes in anteroposterior (AP) diameter of pelvis and caliectasis on USG. Absolute increase in split renal function (SRF) >5% was considered significant. Failure was defined as increase in AP diameter of pelvis and decrease in cortical thickness on 3 consecutive USG, t½ >20 min with obstructive drainage on RS and/or symptomatic patient.

Results:

145 children were included in the study. Their mean age was 3.26 years and mean follow-up was 7.5 years. Pre- and post-operative SRF remain unchanged within 5% range in 35 of 41 patients (85%) in Group I. While 9 of 20 patients (45%) in Group II, 23 of 50 patients (46%) in Group III, and 14 of 34 patients (41%) in Group IV exhibited changes >5% after surgery. 5 patients failed, 2 in Group III, and 3 in Group IV. None of the patients deteriorated in Group I and II.

Conclusion:

After pyeloplasty in children with a baseline split GFR >30%, if a diuretic renogram and USG performed 3 months postoperatively shows nonobstructive drainage with t½ <20 min and decreased hydronephrosis, no further follow-up is required.

Pattern of clinical presentation of congenital anomalies of the kidney and urinary tract among infants and children

AIM

Congenital anomalies of the kidneys and urinary tract (CAKUT) comprise various entities of structural malformations that result from defects in morphogenesis of the kidney and/or urinary tract. These anomalies are the most commonly diagnosed malformations in the prenatal period and constitute the leading cause of end-+stage renal disease (ESRD) in children, worldwide. This prospective study was performed to report the patterns of clinical presentation and diagnosis of infants and children with such malformations.

METHODS

Patients with suggestive features of CAKUT, presenting to Cairo University Children Hospital over one year duration were investigated and categorized based on underlying renal structural/functional malformation and associated extra-renal anomalies.

RESULTS

One hundred and seven CAKUT children were enrolled in the study. Familial clustering was identified in 14% of the cohort and syndromic CAKUT accounted for 31.8% of cases. Different anomaly entities have been identified; posterior urethral valves (PUV) being the commonest detected abnormality (36.4%). Of note, 9.3% of cohort patients had ESRD at presentation, of which 60% had PUV as their primary renal disease. Obstructive cases were noted to present significantly earlier and attain advanced CKD stages rather than non-obstructive ones.

CONCLUSION

CAKUT is a clinically heterogeneous group of diseases with diverse clinical phenotypes. More efforts should be aimed at improving antenatal detection as well as classification with comprehensive reference to the clinical, genetic and molecular features of the diseases. The high frequency of familial and syndromic CAKUT among studied patients is seemingly a convincing reason to pursue the underlying genetic defect in future studies.

The effect of preoperative urinary tract infection on postoperative renal function in prenatally diagnosed ureteropelvic junction obstruction: Indications for the timing of pyeloplasty

PURPOSE

We reviewed renal function after pyeloplasty (PP) in cases of prenatally diagnosed ureteropelvic junction obstruction (PDUPJO) to determine the impact of preoperative urinary tract infection (UTI) on the timing of PP.

METHODS

We retrospectively reviewed 81 cases of PDUPJO diagnosed between 1998 and 2013. Incidence of UTI was used to divide 37 kidneys requiring PP (3 bilateral) into U(-): UTI≤1; n=25, and U(+): UTI≥2; n=12 to compare age at PP, grade of hydronephrosis (HN) on ultrasonography (US), glomerular filtration rate (GFR) on diethylenetriaminepentacetic acid (DTPA) renography, and uptake on dimercaptosuccinic acid (DMSA) scintigraphy pre/post PP.

RESULTS

Age at first UTI and age at PP were similar. HN improved significantly postPP in all cases. Although DTPA and DMSA were similar prePP, improvement postPP was better in U(-) than U(+), but only DMSA in U(-) was statistically significant (15.2%±4.0% vs. 20%±3.7%; p=0.049). There were no complications or UTI postPP.

CONCLUSION

Two or more UTIs would appear to be associated with postPP renal dysfunction in PDUPJO. Thus, PP should be performed after the initial UTI but before the second UTI.

The roles of serum and urinary carbohydrate antigen 19-9 in the management of patients with antenatal hydronephrosis

INTRODUCTION

Serum carbohydrate antigen (CA) 19-9 has been clinically applied as a valuable tumor marker for pancreatic and gastrointestinal carcinoma. CA 19-9 is expressed in normal excretory epithelium tissues. Increased CA 19-9 has also been observed in uroepithelial tumors as well as in nonmalignant conditions including hydronephrosis secondary to ureteral stones.

OBJECTIVE

The purpose of this article is to evaluate the role of urinary CA 19-9 as a non-invasive biomarker in the postnatal differentiation of obstructive and non-obstructive hydronephrosis in patients with unilateral antenatal hydronephrosis.

STUDY DESIGN

Infants with isolated renal pelvic dilatation, defined as the presence of anteroposterior pelvic diameter (APPD) equal to or greater than 7 mm based on antenatal ultrasound after 28 weeks' gestation, underwent systematic investigation for uropathies and were prospectively followed up. The pyeloplasty group consisted of 17 patients with ureteropelvic junction (UPJ) obstruction who had undergone pyeloplasty. The non-obstructive dilatation (NOD) group consisted of 17 patients with non-obstructive hydronephrosis, and the control group consisted of 21 healthy children. Commercial enzyme-linked immunosorbent assay (ELISA) kits were used to measure the urinary and serum CA 19-9 levels. In both hydronephrosis groups (pyeloplasty and non-obstructive dilatation), the correlations between urinary and serum CA 19-9 levels with the anteroposterior pelvic diameter measured at the third trimester and the postnatal initial evaluation and differential renal function were investigated.

RESULTS

The initial median urinary CA 19-9 levels were significantly greater in children who underwent pyeloplasty than in both the non-obstructive hydronephrosis (143 ± 38 vs. 68 ± 23, respectively; p = 0.007) and the healthy control groups (143 ± 38 vs. 13 ± 3, respectively; p = 0.001) (Figure). Three months after surgery, the urinary CA 19-9 levels had decreased significantly according to the preoperative levels in the pyeloplasty group (143 ± 38 vs. 55 ± 16, p = 0.039). In both the pyeloplasty and NOD groups, there was a correlation of urinary CA 19-9 levels with differential renal function and a correlation of serum CA 19-9 levels with the initial anteroposterior pelvic diameter. Receiver operator characteristic (ROC) analysis revealed a better diagnostic profile for the urinary CA 19-9 level than for the serum CA 19-9 level in terms of identifying obstruction in the hydronephrosis groups (areas under the curve = 0.8 and 0.7, respectively). The best cut-off value of for urinary CA 19-9 was 85.5 U/mL with 76% sensitivity, 85% specificity. The negative predictive value was 80%.

DISCUSSION

The results suggest that voided urine CA 19-9 levels seems to be a more useful marker than serum CA 19-9 in obstructive dilatation. An appropriate decrease in urinary CA 19-9 levels after pyeloplasty may be used as a predictor of surgical outcome. In addition, the results have a number of important diagnostic implications that should be further validated in a larger study population.

CONCLUSIONS

Based on these results, we suggest that a high urinary CA 19-9 level is a non-invasive clinically applicable marker for differentiating between obstruction and non-obstructive dilatation.

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

OBJECTIVE

Urinary tract (UT) dilation is sonographically identified in 1-2% of fetuses and reflects a spectrum of possible uropathies. There is significant variability in the clinical management of individuals with prenatal UT dilation that stems from a paucity of evidence-based information correlating the severity of prenatal UT dilation to postnatal urological pathologies. The lack of correlation between prenatal and postnatal US findings and final urologic diagnosis has been problematic, in large measure because of a lack of consensus and uniformity in defining and classifying UT dilation. Consequently, there is a need for a unified classification system with an accepted standard terminology for the diagnosis and management of prenatal and postnatal UT dilation.

METHODS

A consensus meeting was convened on March 14-15, 2014, in Linthicum, Maryland, USA to propose: 1) a unified description of UT dilation that could be applied both prenatally and postnatally; and 2) a standardized scheme for the perinatal evaluation of these patients based on sonographic criteria (i.e. the classification system). The participating societies included American College of Radiology, the American Institute of Ultrasound in Medicine, the American Society of Pediatric Nephrology, the Society for Fetal Urology, the Society for Maternal-Fetal Medicine, the Society for Pediatric Urology, the Society for Pediatric Radiology and the Society of Radiologists in Ultrasounds.

RESULTS

The recommendations proposed in this consensus statement are based on a detailed analysis of the current literature and expert opinion representing common clinical practice. The proposed UTD Classification System (and hence the severity of the UT dilation) is based on six categories in US findings: 1) anterior-posterior renal pelvic diameter (APRPD); 2) calyceal dilation; 3) renal parenchymal thickness; 4) renal parenchymal appearance; 5) bladder abnormalities; and 6) ureteral abnormalities. The classification system is stratified based on gestational age and whether the UT dilation is detected prenatally or postnatally. The panel also proposed a follow-up scheme based on the UTD classification.

CONCLUSION

The proposed grading classification system will require extensive evaluation to assess its utility in predicting clinical outcomes. Currently, the grading system is correlated with the risk of postnatal uropathies. Future research will help to further refine the classification system to one that correlates with other clinical outcomes such as the need for surgical intervention or renal function.

A practical guide to urinary tract ultrasound in a child: Pearls and pitfalls

The aim of this review article is to equip the sonographer with the necessary knowledge to perform a detailed and clinically relevant assessment of the urinary tract in a child. Many of the techniques and principles used in the imaging of the urinary tract in adults can be applied to children. There are, however, notable differences with which the sonographer should be familiar. There is often a certain amount of trepidation when asked to image a child, but there are a number of simple steps that can make the process easier and more fulfilling. This article begins with advice on how to maintain cooperation in a child and the differences in the technical aspects of imaging of children. This is followed by a detailed review of the different pathologies that may be encountered, as well as highlighting information that is particularly relevant to the clinician looking after the child.

Renal teratogens

In utero exposure to certain drugs early in pregnancy may adversely affect nephrogenesis. Exposure to drugs later in pregnancy may affect the renin-angiotensin system, which could have an impact on fetal or neonatal renal function. Reduction in nephron number and renal function could have adverse consequences for the child several years later. Data are limited on the information needed to guide decisions for patients and providers regarding the use of certain drugs in pregnancy. The study of drug nephroteratogenicity has not been systematized, a large, standardized, global approach is needed to evaluate the renal risks of in utero drug exposures.

Hydronephrosis: prenatal and postnatal evaluation and management

Antenatal hydronephrosis (ANH) is one of the most frequently detected abnormalities found on routine prenatal ultrasounds, affecting 1% to 4.5% of all pregnancies. Despite its prevalence, there continues to be uncertainty regarding the clinical impact after birth. Prognosis depends on the severity of the dilation. Expectant prenatal management is the rule with fetal intervention rarely needed in a few select cases. Ureteropelvic junction obstruction and vesicoureteral reflux are the most common postnatal diagnoses. A renal and bladder ultrasound is essential in the follow-up of patients with ANH and helps dictate further investigation with voiding cystourethrography and/or diuretic renography.

The frequency of vesicoureteral reflux diagnosis is correlated with urbanization level of residence in pediatric population: a nationwide study in Taiwan

OBJECTIVE

To investigate the frequency and characteristics of newly diagnosed vesicoureteral reflux (VUR) in children younger than 18 years based on a nationwide database in Taiwan.

METHODS

The present study utilizes a subset of the Taiwan's National Health Insurance Research Database, known as the Longitudinal Health Insurance Database 2005, which contains the data of all paid medical benefit claims over 1997-2007 for a subset of 1,000,000 beneficiaries randomly drawn from the population of 22.72 million individuals during any part of the 2005 calendar year. Our analysis includes the data of all pediatric patients with the diagnosis of VUR.

RESULTS

A total of 738 subjects with VUR diagnosis were identified, including 412 (55.8%) boys and 326 (44.2%) girls. The peak age of VUR occurrence was the first year for males and 1-4 years for females. Approximately 49.7% of all subjects presented with urinary tract infection (UTI); moreover, there were significant differences between genders concerning the presence of UTI (RR = 0.8; p = 0.002). The occurrence rate of VUR in the pediatric population ranged from 2.63 in 1998 to 3.94 in 2003 per 10,000 children during 1998-2005. The frequency of newly-diagnosed VUR in the pediatric population was significantly correlated with urbanization levels of residence.

CONCLUSION

The nationwide, population-based study of pediatric VUR shows there were gender differences in age distribution and presence of UTI. Further studies are warranted to clarify the correlations between urbanization level of residence and occurrence of VUR.

The effect of circumcision on the frequency of urinary tract infection, growth and nutrition status in infants with antenatal hydronephrosis

The objective of this study was to determine the effect of circumcision on the frequency of urinary tract infection (UTI), growth development, and the nutrition status in infants with antenatal hydronephrosis (AH). The data were collected prospectively between 1998 and 2010. Infants with a fetal pelvis diameter of >5 mm identified with antenatal ultrasound were followed-up. Body height and weight were expressed as HZ scores (observed height - median height/standard deviation) and WZ scores (observed weight - median weight/Standard deviation). The nutritional status was evaluated and the body weight was transformed to a weight-for-height index (WHI = weight/median weight for the height age × 100). The HZ and WZ scores or WHI were calculated for each patient at the first and last visits. The chi-square and Student's t tests were used for statistical analysis. A p value <0.05 was considered significant. The study included 178 (134 males, 44 females) patients. Of these, 29 were diagnosed by vesicoureteral reflux (VUR), 87 by obstructive uropathy, and 54 by normal. Of 134 males, 111 infants were circumcised. The mean monitoring time was 45±24.9 months and the mean age of circumcision was 14 ± 16.06 months. The pre-circumcision UTI frequency (2.97 ± 1.14/y) was significantly higher than post-circumcision period (0.25 ± 0.67/y) (p < 0.05). Also, pre-circumcision UTI frequency (2.97 ± 1.14/y) was significantly higher than the UTI frequency observed in female cases (0.85 ± 0.91/y) and in the overall study group (0.73 ± 0.79/y) (p < 0.05). In all patients, the HZ of the circumcised subjects (0.18 ± 1.01) was statistically higher than uncircumcised subjects (-0.26 ± 0.92) (p < 0.05). Although statistically insignificant, the HZ of the circumcised males (0.13 ± 1.24) with VUR was higher than the uncircumcised patients (0.03 ± 0.55) (p > 0.05). In obstructive uropathy groups, the HZ of the circumcised males (-0.13 ± 0.54) was also found to be higher than uncircumcised males (-0.49 ± 0.66) (p < 0.05). Although nutrition scores were found to be better in circumcised males, no statistically significant effect of circumcision on the nutrition status was detected. In conclusion, postnatal early circumcision of infants with AH seems to prevent frequent UTIs and nutritional disturbances enabling normal growth.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Variations in management of mild prenatal hydronephrosis among maternal-fetal medicine obstetricians, and pediatric urologists and radiologists

PURPOSE

There are no current guidelines for diagnosing and managing mild prenatal hydronephrosis. Variations in physician approach make it difficult to analyze outcomes and establish optimal management. We determined the variability of diagnostic approach and management regarding prenatal hydronephrosis among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists.

MATERIALS AND METHODS

Online surveys were sent to mailing lists for national societies for each specialty. Participants were surveyed regarding criteria for diagnosing mild prenatal hydronephrosis and recommendations for postnatal management, including use of antibiotic prophylaxis, followup scheduling and type of followup imaging.

RESULTS

A total of 308 maternal-fetal medicine obstetricians, 126 pediatric urologists and 112 pediatric radiologists responded. Pediatric urologists and radiologists were divided between Society for Fetal Urology criteria and use of anteroposterior pelvic diameter for diagnosis, while maternal-fetal medicine obstetricians preferred using the latter. For postnatal evaluation radiologists preferred using personal criteria, while urologists preferred using anteroposterior pelvic diameter or Society for Fetal Urology grading system. There was wide variation in the use of antibiotic prophylaxis among pediatric urologists. Regarding the use of voiding cystourethrography/radionuclide cystography in patients with prenatal hydronephrosis, neither urologists nor radiologists were consistent in their recommendations. Finally, there was no agreement on length of followup for mild prenatal hydronephrosis.

CONCLUSIONS

We observed a lack of uniformity regarding grading criteria in diagnosing hydronephrosis prenatally and postnatally among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. There was also a lack of agreement on the management of mild intermittent prenatal hydronephrosis, resulting in these cases being managed inconsistently. A unified set of guidelines for diagnosis, evaluation and management of mild intermittent prenatal hydronephrosis would allow more effective evaluation of outcomes.

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.

Fetal genitourinary imaging

The fetal urinary tract is routinely evaluated sonographically beginning in the first trimester with documentation of fetal bladder visualization. Fetal MR might be indicated to further clarify abnormalities found sonographically. The primary imaging modality for evaluation of the fetal kidney is US, which plays an important role in the detection of collecting system dilatation and parenchymal diseases that influence counseling and postnatal care. A commonly seen birth defect affecting the fetal kidney is pyelectasis. The significance of this finding has been extensively evaluated by a number of fetal imaging centers and will be presented in this review. Further topics of interest within the fetal genitourinary system include fetal renal parenchymal disorders and fetal bladder abnormalities. Characteristic imaging features, as well as developmental pathology and differential considerations, are discussed here.

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.

Postnatal outcome of fetal hydronephrosis: implications for prenatal counselling

OBJECTIVES

Hydronephrosis is commonly detected during antenatal scans. There are multiple conflicting prognostic factors in the literature with no clear focus on the postnatal outcome. The aim of the study is to assess the outcome of fetal hydronephrosis, based on antenatal sonography.

MATERIALS AND METHODS

Based on the third trimester fetal ultrasound findings, patients were divided into group I (unilateral hydronephrosis) and group II (bilateral hydronephrosis, ureteric dilatation, bladder thickening, etc). Postnatal evaluation and follow-up was performed by a single physician with uniform protocol. The outcomes, spontaneous resolution vs. surgical intervention, were compared between groups. Among group I, further analysis of outcome was done based on 32-week fetal pelvic antero posterior diameter (APD).

RESULTS

Among a total of 116 patients in the study group; group I had 78 patients, 7 (9%) required surgery; group II had 38 patients, 21(55%) required surgery. The difference in outcome between the groups was statistically significant (P = 0.002). Among those with unilateral hydronephrosis, none (0/55) with APD <15 mm required surgery, while all patients (4/4) with fetal APD> 30 mm required surgery. In those with APD between 15-30 mm, 3/19 required surgery and prolonged follow-up was required to arrive at the decision. The difference in outcome between the subgroups was statistically significant (P< 0.001, Chi-square test).

CONCLUSIONS

The results of our study show that simple unilateral fetal hydronephrosis runs a benign course. In the presence hydronephrosis larger than 15 mm, bilateral disease, or bladder distension, detailed postnatal evaluation and regular follow-up is warranted to plan a timely intervention. The above data could be used in prenatal counselling of these parents. Further larger studies are warranted to through more evidence.

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.

Placebo-controlled trials in pediatric urology: a cautionary view from an ethical perspective

The ethical dispute regarding placebo-controlled trials is discussed in this review. Important issues, such as clinical equipoise, fiduciary obligation and middle ground theory, are examined in the context of pediatric urology clinical research. After reviewing the literature, the authors summarize specific indications for placebo-controlled trials in pediatric urology, and emphasize that physicians have ethical and moral obligations to patients, in the sense that one should carefully plan and conduct such trials in order to gain clinically important information without exposing children to undue risks.

Diagnostic accuracy of postnatal ultrasound screening for urinary tract abnormalities

The study was aimed at (1) the determination of the incidence of abnormalities of the urinary tract in newborn infants detected by postnatal ultrasound screening, and (2) the evaluation of the diagnostic accuracy of postnatal ultrasound screening for detecting surgical urinary tract abnormalities. The prospective study was of full-term neonates born in the University Hospital of Olomouc in 2005-2008 who underwent renal ultrasound screening after 72 h of life. Significant findings were recorded. Subsequent diagnostic and therapeutic procedures were recorded and evaluated in a group of children with detected renal pelvic dilatation (RPD). (1) A total of 6,088 newborn infants was examined. The absolute and relative RPD incidence rates (anteroposterior diameter, APD) were as follows: 5-7 mm, 146 (2.4%); 7-10 mm, 70 (1.15%); 10-15 mm, 13 (0.21%), and 15 mm or more, 5 (0.08%). Of those, 16 children were operated on for abnormalities of the urinary tract, of which nine (56%) had been detected by prenatal screening. Other findings: six cases of unilateral renal agenesis, four cases of multicystic renal dysplasia, four of renal dystopia, one of polycystic kidney disease and one of renal hypoplasia. (2) A group of 224 children with postnatally detected RPD was examined, of whom 40 (17.9%) underwent voiding cystourethrography and/or scintigraphy and 16 (7.1%) were treated surgically. The receiver operating characteristic curves were analyzed, and the areas under the curves were calculated. Postnatal renal ultrasound screening is probably a suitable test for detecting significant urinary tract abnormalities.

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 follow-up of children having antenatal hydronephrosis]

The application of antenatal ultrasound for the evaluation of congenital anomalies in early pregnancy has become a common practice. Hydronephrosis is the most common anomaly observed. Antenatal interventions are experimental and done in advanced centers. Though there are defined criteria of intervention, it is still not clear as to who will benefit. Most patients will have relatively benign course, however identification of those who will have potentially serious postnatal problems permits early intervention. This study gives recommendations for the postnatal examination and follow-up of the newborns having hydronephrosis diagnosed on antenatal ultrasound.

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.

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.

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.