Hidden high-grade vesicoureteral reflux is the main risk factor for chronic renal damage in children under the age of two years with first urinary tract infection

Abstract

Objective. The aim of the present prospective trial was to investigate, in a cohort of young children with first urinary tract infection (UTI) and negative prenatal history, the role of imaging in screening babies at risk of renal deterioration. Material and methods. Children who had experienced the first febrile UTI at or under the age of 2 years were enrolled. They had had normal foetal routine ultrasound. All the children underwent renal ultrasound after admission; those with sonographic signs of obstruction were excluded. Voiding cystoureterogram (VCUG) and ^99mTc-dimercaptosuccinic acid (DMSA) scintigraphy were performed approximately 1 month and 6 months after the UTI, respectively. Finally, 65 babies (47.7% males, 38.6 ± 1.3 weeks of gestational age) were prospectively followed up. Results. In 15.4% and 29.2% of cases, the renal pelvis was ≤7 and >7 mm in diameter, respectively. Vesicoureteral reflux (VUR) was detected in 55.4% of the children and renal scarring in 18.5%. Stepwise binary logistic regression analysis showed that the severity of VUR correlated significantly with renal scarring, excluding all the other variables from the model. In this cohort of babies, the severity of VUR seriously enhanced the risk of renal damage (odds ratio = 6.658, p = 0.004). Conclusion. Follow-up renal scintigraphy 6 months after a UTI can predict severe VUR in very young children showing renal scarring, detecting only those who are at risk of loss of kidney function and who would require further assessment. After the first episode of UTI, the practice of performing VCUG in babies with normal DMSA scintigraphy is of doubtful value.

Key Words::

• Children
• DMSA scintigraphy
• pyelonephritis
• ultrasound
• urinary tract infection
• vesicoureteral reflux

Declaration of interests: No funding was received.