[Vesicoureteral reflux grades III-IV: factors involved in the efficacy of endoscopic treatment in pediatric patients].

Objectives: Vesicoureteral reflux (VUR) is detected in 30-50% of pediatric patients diagnosed of urinary tract infection (UTI). Multiple clinical trials have compared the results of conservative management against surgical therapy. The introduction of a third alternative in 1984 (endoscopic approach) has dramatically modified the management of VUR. The objective of our work is to analyze the factors influencing the favourable outcome of the endoscopic treatment of VUR.
Methods: Retrospective and prospective cohort study analyzing 90 patients with grades III and IV VUR treated endoscopically over the last eight years. 184 patients undergoing endoscopic management were selected from a group of 550 patients (735 VUR renal units) with the diagnosis of VUR over the study period. All patients underwent VCUG or galactose-based sonocystography to obtain the diagnosis. DMSA scintigram was used to evaluate renal damage. Data about gender, age, UTI, bilateralism, renal damage, voiding dysfunction, outcomes, complications, and recurrences were registered. A new factor was defined: ureteral dilation independent from the international classification. This factor was evaluated by a single pediatric urologist blinded for the international classification results. Data analysis was performed using the chi square test and Fischer exact test; a multiple logistic regression analysis was also performed. Statistical significance was established at p < 0.05. SPSS 11.0 software was employed for data analysis.
Results: Boys/girls ratio was 2.91. Bilateral VUR appeared in 44.4% of the cases. UTI was the presenting diagnosis in 64 cases; the diagnosis was prenatal in 21 cases (with a male predominance 5.2:1). We found a strong correlation between renal scarring at the time of diagnosis and voiding dysfunction (p< 0.01). Cure rate after first injection was 64%. Although univariate analysis showed a strong correlation between cure and first injection, biloterality, voiding dysfunction, initial nephropathy, and ureteral dilation grade, on multivariate logistic regression the only significant factor to predict treatment response was the existence of severe ureteral dilation in comparison with mild dilation (p < 0.001; odds ratio 0.045, 95% confidence interval 0.01-0.16). Renal damage progression was specially detected in those patients with voiding dysfunction (p = 0.053), bilaterality (p = 0.034) and severe ureteral dilation (p < 0.001).
Conclusions: A direct relation between cure rate after endoscopic treatment of grade III and IV reflux and severity of ureteral dilation was demonstrated. Other relevant factors implied in the endoscopic resolution of VUR include the existence of voiding dysfunction, bilateral reflux and renal damage determined by DMSA at the time of initial diagnosis. Gender, age, and number of infections during follow up have no influence in the probability of cure of grade III and IV VU reflux treated with subureteral injection of biocompatible substances.