Objective: To examine, in infants presenting with vesico-ureteric reflux (VUR), the relationship between the presence of initial renal abnormalities with the outcome of VUR and bladder function at 16 months of age.
Patients and methods: The study group comprised 40 infants (32 boys) presenting consecutively (29 after prenatal detection) with VUR grade III or greater (bilateral in 29) on the initial micturating cystogram (median age 8 weeks). The initial presence of abnormal kidneys was determined from isotopic renography and/or ultrasonography. These data were correlated with the outcome of VUR, from direct isotope cystography, and bladder function assessed by natural filling urodynamics, examined at age 16 months (mean 16.4 months, SD 2.1).
Results: Three groups were identified. Group 1 (eight boys and six girls) had normal kidneys bilaterally; initially grade III VUR was common. At 16 months bladder function was normal in 10 children and none had VUR (complete resolution). Group 2 (14 boys and two girls) had unilateral renal abnormalities; initially VUR was predominantly grade IV or grade V. At 16 months bladder function was normal in eight children and VUR resolved in eight, five of these with normal bladder function. Group 3 (10 boys) had bilateral renal abnormalities. Initially grade V VUR predominated; at 16 months the bladder function was normal in only one, and in the rest the emptying dynamics were abnormal. All 10 boys had persisting VUR (no resolution).
Conclusions: In infants with moderate or severe VUR, resolution at 16 months old is associated with normal kidneys in a similar proportion of boys and girls. Resolution also correlates well with normal bladder function. Presentation in infancy with bilateral abnormal kidneys, associated with severe VUR in boys, is a poor prognostic sign for the early outcome of VUR and for bladder function.