Prevalence and predictors of renal functional abnormalities of high grade vesicoureteral reflux

The association of vesicoureteral reflux, febrile urinary tract infections and renal parenchymal damage is well recognized. We determined the prevalence and predictors of renal functional abnormalities in children with high grade vesicoureteral reflux.

We retrospectively reviewed the medical records and dimercapto-succinic acid scans of 774 consecutive children with primary high grade vesicoureteral reflux (grade IV-V) seen at our institution between 1998 and 2011. For multivariate analysis we analyzed variables associated with renal functional abnormalities, such as presentation history, age, gender and reflux grade, in a logistic regression model.

Of the children 698 (90%) and 76 (10%) had grade IV and V reflux, respectively. Dimercapto-succinic acid scans revealed renal functional abnormalities in 291 children (37.6%), including 240 (34%) with grade IV and 51 (67%) with grade V reflux. Univariate analysis showed that age greater than 1 year (OR 2.95, p <0.001), grade V reflux (OR 4.09, p <0.001) and preoperative bladder/bowel dysfunction (OR 2.94, p = 0.026) were significant predictors of renal functional abnormalities. Multivariate analysis showed that age greater than 1 year (OR 3.45, p = 0.001) and grade V reflux (OR 5.89, p <0.001) were the most significant independent predictors of such abnormalities.

There is an increased risk of renal functional abnormalities in children older than 1 year and those with grade V vesicoureteral reflux. Patients with a history of bladder/bowel dysfunction are also at greater risk for such abnormalities. The early detection and treatment of high grade vesicoureteral reflux may prevent acquired renal parenchymal damage and limit the progression of renal damage in patients with congenital reflux nephropathy.