Long-term outcome of prenatally detected posterior urethral valves: single center study of 65 cases managed by primary valve ablation.

PURPOSE: Management of posterior urethral valves is significantly modified by the prenatal diagnosis. Our aim was to assess long-term outcome of children with prenatally detected posterior urethral valves treated at our institution by primary valve ablation without routine urinary drainage or diversion. MATERIALS AND METHODS: A total of 79 cases of posterior urethral valves were detected prenatally at our hospital between 1987 and 2004. Of these cases 65 were managed postnatally, while pregnancy was terminated in 14. We studied the prenatal parameters of gestational age at diagnosis, renal parenchyma on ultrasound and amniotic fluid volume. Fetal urine was analyzed when indicated. Long-term outcome was assessed. RESULTS: Primary valve ablation was done in all cases except 2. Median followup was 6.8 years (range 1 to 14.3). At the end of followup there were 11 cases of renal failure (17%) with 5 detected before 24 weeks of gestation, 6 cases of oligohydramnios and 9 cases of abnormal parenchyma. Gestational age at diagnosis and oligohydramnios were statistically significant predictors of final renal outcome (p = 0.003 and p = 0.02, respectively), while renal parenchymal changes were not (p = 0.23). When fetal urinalysis detected good prognosis (12 cases) renal failure developed in none, compared to 2 of the 3 cases with a bad prognosis. Continence was achieved in 42 of 55 toilet trained children (76%), 3 had nocturnal enuresis and 10 (18%) were incontinent. CONCLUSIONS: Our long-term results of prenatally detected posterior urethral valves confirm that early valve ablation can be considered as the primary treatment in the majority of patients, without the need for preoperative drainage or diversion. Gestational age at diagnosis and volume of amniotic fluid are significant predictors of postnatal renal outcome.