Features of primary vesicoureteral reflux and renal damage in children at a single institution in Brazil from 1969 to 1999

Objectives: The purpose of the study wasto evaluate the clinical/radiological featuresof patients with primary vesicoureteral reflux(VUR) admitted to a single institution from 1969to 1999.Methods: The patients' records wereretrospectively reviewed and the followingclinical data obtained at admission wereanalyzed: age, gender, race, date of entry,previous symptoms, weight, height, bloodpressure, and serum renal function. The renalimaging tests at baseline were alsoretrospectively analyzed including voidingcystourethrography, excretory urography, DMSAscan, and ultrasonography. For statisticalanalysis, reflux was classified into twocategories: (1) mild/moderate (grade I/II/III)and (2) severe (grade IV/IV). Renal damage wascategorized according to the followingclassification: (I) mild, focal damage; (II)moderate, more extensive scars, and (III)severe, generalized damage or shrunken kidney.The odds ratio (OR) and the respectiveconfidence interval (95%CI) were calculated tocompare the difference in risk between groups.Results: A total of 461 patients wereenrolled in the protocol. There was apredominance of female gender (71%) and whiterace (73%). Mean age at VUR diagnosis was 2.8y and 93% of the patients had urinaryinfection before admission. Bilateral refluxwas diagnosed in 249 (54%) children, for atotal of 710 renal units for study. Thedistribution of reflux grade was as follows:grade I (7%); II (36%); III (26%); IV(23%), and V (8%). Of the 450 childreninvestigated, 180 (40%) presented with renaldamage, for a total of 234 (26%) units withrenal scars. Renal damage was associated withthe following factors: Diagnosis after 2 y ofage (OR = 1.5, 95%CI = 1.08–2.1, p =0.01), severe degree of reflux (OR = 6, 95%CI= 4–9, p < 0.001). There was asignificant risk of severe renal damage formale gender (OR = 1.9, IC95% = 1.3–2.1, p =0.001).Conclusion: There was a predominance ofrenal damage in children diagnosed above 2 yand with a high degree of reflux. Severe renaldamage was associated with male gender.