Multicystic dysplastic kidney and contralateral vesicoureteral reflux. Renal growth.

BACKGROUND: To evaluate if vesicoureteral reflux (VUR) contralateral to the multicystic dysplastic kidney can interfere with the compensatory renal hypertrophy. METHODS: Twenty-seven patients (17 males, 10 females) with multicystic dysplastic kidney (MDK) (14 on the right, 13 on the left) have been treated at the Nephrology Unit of the Pediatric Department of the University of Verona from birth up to the second year of life. All these patients were diagnosed as having MDK by prenatal ultrasonography. Seven children (4 males and 3 females) had VUR (5 monolateral, 2 bilateral), diagnosed at the end of the first month of life. After diagnosis children underwent antibiotic prophylaxis with beta-lactam compounds at low doses. Four patients underwent a surgical correction of VUR associated with nephrectomy within the second year of life. The remaining 3 patients were treated with antibiotic prophylaxis; a progressive resolution or downgrading of reflux grade took place respectively in 1 and in 2 of them. Only 6 children with MDK underwent nephrectomy. Renal growth was studied by serial echographic measurements of the longitudinal renal lenght (performed at birth, at 6 months, and at 2 years of life). RESULTS: Renal length was 5.68+/-1.24 cm, 6.72+/-0.88 cm, 8.56+/-1.27 cm in children without VUR, respectively at birth, 6 months and 2 years of life. Renal length was 4.65+/-0.63 cm, 6.70+/-0.64 cm, 7.07+/-1.14 cm in children with VUR, respectively at birth, 6 months and 2 years of life. A statistically significant difference was observed between the two groups at birth (p<0.05) and at 2 years of life (p<0.01). CONCLUSIONS: The conclusion is that VUR contralateral to the MDK is associated with small kidneys and reduced renal growth both at birth and at 2 years of life.