Mild hydronephrosis in newborns and infants: can ultrasound predict the presence of vesicoureteral reflux

Abstract

The objective of our study was to determine the significance of mild hydronephrosis in newborns and infants as an indicator of vesicoureteral reflux (VUR). The voiding cystourethrography (VCUG) of 573 patients aged 0-18 months with mild, sonographically detected hydronephrosis were reviewed for VUR. Patients with secondary reflux or anomalies making an exact reflux grading impossible were excluded. Normal kidneys, contralateral to hydronephrotic ones, were included. Each kidney was considered separately, forming a total of 1,146 renal units. Mild hydronephrosis was defined as an anteroposterior diameter of the renal pelvis of 0.5-1.5 cm without caliectasis. The International Grading System was used to grade VUR. Seven hundred and thirty-six kidneys had mild hydronephrosis. VUR occurred in 189 out of 736 (25.7%) of these kidneys, and in 108 out of 410 (26.3%) non-distended kidneys, contralateral to hydronephrotic ones (p=0.806). No statistical differences in the frequency of VUR and dilatation were found between the subgroups of patients with and without infection, except for a higher grade of reflux in the group with infection. The frequency of VUR in mildly dilated kidneys was not significantly different from that in non-distended ones. There was a poor correlation between VUR and mild hydronephrosis. The latter should not be considered in itself an indication for VCUG in asymptomatic neonates and infants.

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

“…This is consistent with our findings of reflux in 27% of infants with UTI. Moreover, VCUG revealed VUR in 35.6% of infants with previous abnormal renal ultrasound, and in patients with normal renal ultrasound, VUR was also present in 21.7% of cases; therefore, a normal postnatal renal ultrasound does not preclude the presence of reflux [28,39,40]. In a recent retrospective hospital-based cohort study, high procalcitonin was found to be a strong and independent predictor of VUR and may be used to identify low-risk patients to avoid unnecessary VCUG [41].…”

“…The combination of VUR and UTI may predispose children to pyelonephritis, renal scarring, hypertension, and chronic renal disease [25][26][27][28][29]. However, recommendations regarding the specific radiographic studies required to evaluate neonates and infants younger than 2 months with UTI are lacking, although renal ultrasound and VCUG are frequently performed.…”

Postnatal Assessment and Outcome of Infants with Antenatal Hydronephrosis

“…Önceleri AH saptanan tüm bebeklere proflaktik antibiyotik kullanımı önerilmesine karşın, son dönemlerde yalnızca seçilmiş olgularda antibiyotik kullanımı önerilmektedir (3,4). Hangi bebeklerin miksiyon sistoüreterografi (MSUG) ile değerlendirilmesi gerektiği konusunda da tartışmalar mevcuttur (5,6). AH takibinde önemli diğer bir zorluk ise, yeni doğan bir bebeğe sürekli antibiyotik kullanımı ya da girişimsel radyolojik uygulamalar gibi ebeveynleri endişelendiren önerilerde bulunmaktır.…”

Predictive Markers for Screening Renal Damage in Children with Urinary Tract infections and Vesicoureteral Reflux

“…This study also included patients with UTIs, and there was no statistically significant relationship between mild hydronephrosis and the presence of a UTI. However, UTI incidence was significantly higher in patients with VUR grade 3 or higher than in those with a lower grade VUR, regard-less of the presence of hydronephrosis during the follow-up period 24) . According to another study published in 2008, studies in infants under 3 months of age also found that kidney sonography was statistically significant in predicting the presence of VUR in high grade VUR children 25) .…”

“…Indeed, a different study also suggested that prenatal hydronephrosis with high grade VUR may pose as a risk factor for UTIs 20) . Kidney sonography can be used to predict VUR in neonates and infants [21][22][23][24] . In a study on 735 infants diagnosed with mild hydronephrosis, 189 infants (25.7%) had VUR.…”