The Swedish infant high-grade reflux trial: UTI and renal damage

SummaryIntroductionHigh-grade vesicoureteral reflux (VUR) in children is associated with recurrent urinary tract infection (UTI) and renal damage. Breakthrough UTI despite continuous antibiotic prophylaxis (CAP) during the first years of life is a matter of concern and evokes early intervention. We investigated whether early endoscopic treatment (ET) of VUR grade 4-5 can reduce the risk of UTI recurrence and renal scarring.Materials and methodsThis prospective, randomized, controlled, multicentre, 1-year follow-up trial comprised 77 infants, <8 months of age with VUR grade 4-5 (Table) randomized to CAP (n = 39) or ET (with prophylaxis until resolution) (n = 38). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year. Parenchymal defects were seen in 67 (87%) children at entry, 39 (34 boys, 5 girls) of them characterized as generalized. At follow-up, renal deterioration (new scars or progress in old damaged area) and symptomatic UTIs were reported.ResultsThere were 27 recurrent febrile UTIs in 6 (16%) children in the ET group and in 10 (26%) in the CAP group (p = 0.43), in eight (36%) girls and eight (15%) boys (p = 0.039). Successful VUR outcome (VUR 0-2) was seen in 22 (59%) in the ET and eight (21%) in the CAP group (p = 0.0014). Multiple recurrences were only seen in patients with persistent dilating reflux at follow-up (p = 0.019). Deterioration on scintigraphy was seen in eight children (9 kidneys) with no difference between treatment groups (p = 0.48) or sex (p = 0.17). Renal deterioration was associated with high bladder capacity (BC) and large residual volume (PVR) at 1 year (p = 0.0092 and p = 0.041). Six of the eight children with renal deterioration had a recurrent UTI (p = 0.0032). Seven of nine renal units with deterioration were seen in children with persistent VUR 3-5 at follow-up. Univariable logistic regression identified female sex and high PVR as positive predictors for recurrent UTI (p = 0.039 and 0.034) and high PVR tended to predict renal deterioration (p = 0.053).DiscussionNo differences between the treatment groups regarding recurrent UTI and renal deterioration could be found. Increased PVR and female sex were positive predictors for UTI recurrences. VUR grade at follow-up was correlated to UTI recurrence and renal deterioration.ConclusionThis study did not show any difference between ET and CAP in reducing the risk of UTI recurrence or renal deterioration. The rate of VUR resolution was higher in the ET group and VUR grade at follow-up correlated with both UTI recurrence and renal deterioration.Table. Baseline demographics and the primary outcome in the total study population and per treatment group.VariableTotal (n = 77)Endoscopic treatment (n = 38)Prophylaxis (n = 39)pBaselineSex Girls22 (29%)12 (32%)10 (26%) Boys55 (71%)26 (68%)29 (74%)0.75Age at randomization (months)6.7 (4.1-9.2)6.8 (4.1-9.2)6.7 (4.7-8.8)0.65Grade of VUR 430 (39%)15 (40%)15 (39%) 547 (61%)23 (61%)24 (62%)1.00Bilateral VUR52 (68%)25 (69%)27 (69%)0.94Renal damage67 (87%)32 (84%)35 (90%)0.701-year follow-upFebrile UTI during study16 (21%)6 (16%)10 (26%)0.43Renal deterioration8 (11%)3 (8%)5 (14%)0.74Note. For categorical variables n (%) is presented. For continuous variables mean (range) is presented.