Congenital malformations of the urinary tract: progression to chronic renal disease.

Introduction: Congenital nephrourological abnormalities (CAKUT) are a particularly relevant group of diseases due to their high prevalence and the fact they are the main cause of chronic renal disease (CRD) in the pediatric population. Our objective was to determine the characteristics and prevalence of CAKUT in our setting, while identifying the factors associated with the occurrence of renal damage.

Materials and methods: A retrospective, descriptive, analytical, cross-sectional study of patients seen in the Pediatric Nephrology Department of a third-level hospital from January 1 to December 31, 2018 was carried out. Epidemiological, clinical, and analytical variables were assessed, and potential risk factors associated with CRD were searched for.

Results: The study involved 685 patients with 827 kidney units affected by CAKUT with a mean age of 9.98 ± 5.12 years. 62.2% were male, and the mean follow-up period after diagnosis was 9.95 ± 5.09 years. 58.8% were non-obstructive dilations, followed by renal dysplasia, obstructive dilations, and number and position abnormalities. The most frequent malformation was vesicoureteral reflux (VUR). The most commonly affected side was the left (47.5%). 55% of the diagnoses were prenatal. 172 patients underwent surgery. The initially chosen treatment for VUR was endourological. Overall re-intervention rate was 20%. Of the total number of patients, glomerular filtration rate was analyzed in 383, 95 (24.8%) of whom had CRD (86% in stage 2). Male sex, bilaterality, and proteinuria were risk factors associated with CRD.

Conclusions: Knowledge of the epidemiological and clinical characteristics of children with CAKUT and the factors associated with CRD helps to individualize the clinical follow-up of these patients, thus customizing diagnostic tests and healthcare resources.