5-Year Prospective Results of Dimercapto-Succinic Acid Imaging in Children With Febrile Urinary Tract Infection: Proof That the Top-Down Approach Works

Abstract

Evaluation in children after febrile urinary tract infection involves voiding cystourethrogram, which emphasizes urinary reflux rather than renal risk. We believe that early dimercapto-succinic acid renal scan after febrile urinary tract infection predicts clinically significant reflux and which children should undergo voiding cystourethrogram. The criticism of this approach is that some reflux and preventable renal damage would be missed. This study validates the use of initial dimercapto-succinic scan and presents 5-year renal outcomes. We prospectively studied children with febrile urinary tract infection using initial dimercapto-succinic acid renal scan, voiding cystourethrogram and renal/bladder ultrasound. Children with anatomical or neurological genitourinary abnormality and protocol failures were excluded from analysis. Dimercapto-succinic acid scan was repeated at 6 months if initially abnormal. Followup was done every 6 months in all children for at least 5 years. A total of 121 children fit study inclusion criteria and completed the 5-year study. Overall 88 initial dimercapto-succinic acid scans (73%) were abnormal and 78 children (64%) had urinary reflux. The OR of having clinically significant reflux predicted by abnormal initial scan was 35.4. Abnormal followup scan did not predict clinically significant reflux. Overall subsequent urinary tract infection developed in 32 patients (26.5%) and 27 (85%) had an abnormal initial scan. No child with a normal initial scan had clinically significant reflux. Dimercapto-succinic acid scan can predict clinically significant reflux and children at greatest renal risk. Initial dimercapto-succinic acid scan should be done in all children after febrile urinary tract infection while voiding cystourethrogram should be reserved for those with an abnormal initial dimercapto-succinic acid scan.