Long-term follow up of antenatally diagnosed megaureters.

AIM: We have retrospectively evaluated our 17 years of experience with antenatal diagnosis of hydronephrosis that led to postnatal diagnosis of megaureter, and tried to determine criteria for surgery. PATIENTS AND METHODS: Seventy-nine children (64 boys and 15 girls) with antenatal diagnosis of hydronephrosis that led to postnatal diagnosis of megaureter were followed conservatively over a period of 18 years (1988-2006). Right ureterohydronephrosis was seen in 23 children, left in 30 and 26 had bilateral ureterohydronephrosis comprising a total of 105 renal units (RU). According to SFU (Society for Fetal Urology) classification, 8 RU were grade 1, 57 grade 2, 29 grade 3 and 11 grade 4 postnatal hydronephrosis. Mean ureteral diameter was 1.2 cm. Relative renal function was in 82 RU more than 40%, in 18 RU 30-40% and in 5 RU less than 30%. Functional deterioration of the hydronephrotic kidney of more than 5%, worsening of hydronephrosis (SFU upgrade) and a persistent obstructive curve on radionuclide scans were the main indications for surgery. RESULTS: Twenty-five (31%) children required surgical correction. Mean age at surgery was 14.3 months (range 3-60). Univariate analysis revealed that gender and side of obstruction are not significant predictive factors for surgery SFU grade 3-4 of postnatal hydronephrosis, Relative renal function less than 30% and ureteral diameter more than 1.33 cm were significant independent risk factors leading to reimplantation. CONCLUSIONS: Only 30% of children with antenatal diagnosis of megaureter required surgical correction. Renal function less than 30%, grades 3 and 4 hydronephrosis, and ureteric diameter more than 1.33 cm are statistically significant and independent predictive factors for surgery.