Long-term follow up of antenatally diagnosed megaureters

Abstract 

Aim

We have retrospectively evaluated our 17years 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 18years (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 1.2cm. 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 14.3months (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 1.33cm 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 1.33cm are statistically significant and independent predictive factors for surgery.

Keywords: Congenital megaureter, Conservative treatment, Antenatal hydronephrosis