The management of renal conditions in the perinatal period

Bilateral subdiaphragmatic renal ectopia with associated congenital anomalies: a case report and systematic review of cases

Background

Cephalad renal ectopia is rare. Ectopic kidneys besides being prone to various pathologies are occasionally associated with other congenital abnormalities. To the best our knowledge, at the time of this writing, only ten cases of bilateral subdiaphragmatic renal ectopia had been reported.

Case presentation: We present a rare case of bilateral subdiaphragmatic ectopic kidneys incidentally discovered during evaluation of the abdominal pain. In addition, our patient had associated anomalies of the liver, spleen and mesocardia.

Conclusions

Recognition of this condition is important for accurate diagnosis, surgical and/or intervention planning, as well as identifying other associated anomalies.

Pediatric congenital hydronephrosis (ureteropelvic junction obstruction): Medical management guide

The prevalence of asymptomatic hydronephrosis, now detected by ultrasonography, has increased. However, definitive management guidelines for the management of congenital hydronephrosis have not been established. The Japanese Society of Pediatric Urology created a "medical management guide" based on new findings for physicians practicing pediatric urology. We developed a medical management guide focused on congenital hydronephrosis caused by ureteropelvic junction obstruction. This medical management guide consists of the definition, pathophysiology, epidemiology, diagnosis, classification, treatment using a clinical management algorithm of hydronephrosis and the long-term course of the disease. The aim of hydronephrosis management is to determine whether surgery should be carried out to avoid renal dysfunction, as there is a possibility for improvement without intervention. Ultrasonography is essential to make treatment decisions. Management is determined by a comprehensive assessment, including the degree of hydronephrosis, anterior-posterior diameter of the renal pelvis and, if necessary, a nuclear medicine evaluation of the status of urine drainage and renal function.

Postnatal imaging of neonates with prenatally diagnosed genitourinary abnormalities: a practical approach

The advent of prenatal US and, more recently, fetal MRI has changed our pattern of referrals. In the current clinical algorithms, most neonates evaluated for genitourinary abnormalities are asymptomatic. These infants are referred for multidisciplinary consultation, imaging and surveillance. Evaluation of these children commences following pertinent review of available prenatal studies; this is appropriate, as in certain instances prenatally gathered information of potential prognostic significance can be inferred or can obviate the need for multiple examinations. US remains the first-line imaging modality for diagnosing urinary abnormalities in neonates and young infants, although it offers primarily morphological assessment. However, US coupled with MAG-3 scanning results in a powerful combination that provides anatomical and functional information. Recently, MRI and MR urography have been increasingly regarded as one-stop-shop examinations that can deliver both anatomical and functional information, and play an increasing role in the evaluation of ureteral ectopia and genital anomalies. Fluoroscopic examinations are reserved to exclude vesicoureteral reflux, to delineate urethral obstruction or to provide additional information to support a diagnosis. A practical approach to postnatal imaging of the neonate is discussed and the important genitourinary anomalies in this age group are presented and illustrated.

Fetal counselling for surgical conditions

Foetal counselling is best achieved by a multidisciplinary team that can favourably influence the perinatal management of prenatally diagnosed anomalies and provide this information to prospective parents. Prenatal diagnosis has remarkably improved our understanding of surgically correctable congenital malformations. It has allowed us to influence the delivery of the baby, offer prenatal surgical management and discuss the options of termination of pregnancy for seriously handicapping or lethal conditions. Antenatal diagnosis has also defined an in utero mortality for some lesions such as diaphragmatic hernia and sacrococcygeal teratoma so that true outcomes can be measured. The limitation of in-utero diagnosis cannot be ignored. The aim of prenatal counselling is to provide information to prospective parents on foetal outcomes, possible interventions, appropriate setting, time and route of delivery and expected postnatal outcomes, immediate and long term.

Dynamic ultrasound study on urinary bladder in infants with antenatally detected fetal hydronephrosis

To evaluate bladder function in infants with antenatally diagnosed hydronephrosis (ANH) using dynamic ultrasound protocol. Forty consecutive male infants (mean, 0.25 y) with ANH and 33 age-matched normal controls (mean, 0.49 y) were recruited. Anteroposterior (AP) diameter of renal pelvis (RP) and hydronephrosis index [HI = anteroposterior diameter of RP of kidney divided by urinary bladder volume (BV)] were calculated. Maximum BV (MaxBV) was determined just before voiding. Residual volume (RV) and bladder wall thickness (BWT) were measured after spontaneous voiding. Thirty-one infants (77.5%) showed persistently dilated RP postnatally in which 12 (39%) showed significantly high HI. In general, ANH infants had smaller MaxBV (30.71 versus 52.45 mL), larger residual volume (2.47 versus 1.93 mL), and larger BWT (4.4 versus 3.7 mm) than normal (p < 0.05, Mann-Whitney test). Infants with abnormally high HI had significantly more disturbed bladder parameters [smaller MaxBV (23.33 versus 33.49 mL) and larger BWT (4.67 versus 3.79 mm)] than the normal HI group (p < 0.05, Mann-Whitney test). Abnormal functional bladder parameters were evident in ANH infants. We postulated that immature function in the pelviureteric junction was associated with bladder dysfunction in these infants. Dynamic ultrasound protocol might help to understand the underlying pathophysiology of urinary system in ANH infants.

Management in children of mild postnatal renal dilatation but without vesicoureteral reflux

Infants with mild postnatal renal dilatation but without vesicoureteral reflux pose a challenge. For how long and in what way should they be followed? From May 1989 to December 2006, we prospectively followed 1,795 pregnancies in which the foetal renal pelvis measured 4 mm or greater. Voiding cystourethrography (VCUG) and renal ultrasound were performed on 1,315 infants at 6 weeks of age. Our study group comprised 208 (167 male) infants with normal VCUG findings who had a renal pelvis of 6-11 mm. We followed them for 1-17 years (mean 11 years). Medical and radiological records were reviewed to determine any urinary symptoms and final outcome. They underwent, on average, four further imaging tests. The renal dilatation had resolved by 24 months in approximately 70%. Urinary tract infection (UTI) developed in 16 (8%). Calyceal dilatation was more likely in those developing UTI (P=0.02). Twenty-two (10.6%) had a radiologically demonstrated urinary tract abnormality. Of the five who had renal scarring or severe obstruction, four became symptomatic. Most infants with mild postnatal renal dilatation can be investigated with only one further sonogram at 24 months of age. Mild postnatal renal dilatation is associated with subsequent UTI or renal tract abnormality in 18%. Severe renal abnormality occurred in 2.4%.

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.

Comparative efficacies of procalcitonin and conventional inflammatory markers for prediction of renal parenchymal inflammation in pediatric first urinary tract infection

OBJECTIVES

To compare the reliability of procalcitonin (PCT) with conventional laboratory parameters in predicting for renal parenchymal inflammation (RPI).

METHODS

The study cohort consisted of 57 children who were admitted for a first-episode urinary tract infection. All patients underwent measurement of the leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum PCT. RPI was evaluated by technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. If the first DMSA findings were abnormal, another analysis was performed 6 months later. The cutoff points for ESR, CRP, and PCT were established by comparing the areas under their receiver operating characteristic curves. Statistical analysis was performed using 1-way analysis of variance.

RESULTS

Of the 57 children, 27 were diagnosed with RPI on the basis of positive DMSA results. The ESR, CRP, and PCT levels were significantly greater (P < .001) in the patients with RPI than in those without RPI. In contrast, the leukocyte count was the same in both groups (P > .05). PCT was a more sensitive and specific marker for differentiating upper and lower urinary tract infection than ESR and CRP. Persistent lesions at the site of previous RPI were found in 12 patients in the follow-up DMSA analysis, with total regression evident in the remaining 15. The PCT levels were significantly greater in those with persistent renal lesions than in those with total regression (P = .005).

CONCLUSIONS

Serum PCT is a more reliable biologic marker than the ESR, CRP, or leukocyte count for the early prediction of RPI in children with a first episode of urinary tract infection. In addition, the greater the elevation of PCT at admission, the more positive the correlation for subsequent permanent renal damage.

MRI with diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) assessment in the evaluation of normal and abnormal fetal kidneys: preliminary experience

OBJECTIVE

To investigate apparent diffusion coefficient (ADC) mapping with the measurement of renal tissue ADC value of normal and pathological fetal kidneys at various gestational ages (GAs).

METHODS

Fifty pregnant women underwent magnetic resonance images (MRI) after ultrasound (US) for suspected fetal genitourinary disorders (16) or for suspected disorders in other organs (34). A multiplanar study of urinary system was obtained by using conventional T2-weighted sequences and echo planar imaging (EPI); Diffusion-weighted images and ADC maps were evaluated. The renal tissue ADC value was measured for all normal and abnormal fetuses and related to GA.

RESULTS

MRI confirmed urinary anomalies in 15 fetuses [2 renal developmental variants, 2 nephropathies, 4 multicystic dysplastic kidneys (MCDK), 7 renal tract dilatations] and detected normal kidneys in the remaining 35 fetuses. Normal renal parenchyma showed bright signal on diffusion-weighted images with ADC values ranging from 1,065 to 1,327 microm(2)/s with a tendency to decrease over GA. A pathological ADC was detected in cases of bilateral MCDK, huge dilatations and in cases of nephropathies.

CONCLUSION

Diffusion-weighted imaging (DWI) with ADC mapping can be used in the evaluation of fetal renal parenchyma and may become a tool of assessing function of the fetal kidney by means of measurement of renal tissue ADC values.