Posterior urethral valves: does young age at diagnosis correlate with poor renal function?

OBJECTIVES

To determine whether young age at presentation is associated with poor renal function in patients with posterior urethral valves (PUVs). Previous studies have indicated that a young age at diagnosis is an adverse prognostic factor for patients with PUVs.

METHODS

Fifty-three children with PUVs were diagnosed between January 1998 and March 2000. The patients included 25 infants with a median age of 3 months (group 1) and 28 children with a median age of 3.5 years (group 2). No statistically significant difference was present between the two groups regarding presenting symptoms, incidence of hydronephrosis, bilateral vesicoureteral reflux, presence of popoff mechanisms, or number of positive urinary cultures at presentation. Primary valve ablation was carried out in all patients. The median follow-up period for groups 1 and 2 was 19 and 18.5 months, respectively (P <0.05).

RESULTS

The percentage of serum creatinine deviation greater than the normal age-reference range was calculated for each patient at diagnosis and at the last follow-up visit. The median percentage of serum creatinine deviation at presentation was 190% for group 1 and 22% for group 2 (P >0.05). The median percentage of serum creatinine deviation at the last follow-up visit was nil for group 1 and 10% for group 2 (P <0.009). Persistently dilated upper tracts were noted in 48% and 86% of patients in groups 1 and 2, respectively (P <0.004).

CONCLUSIONS

In contrast to the findings of previous studies, we provide evidence of a less favorable outcome with delayed presentation of PUVs relative to those diagnosed in the first year after birth in respect to renal function and upper tract dilation.