Urodynamic findings in boys with posterior urethral valves after treatment with primary valve ablation or vesicostomy and delayed ablation.

PURPOSE

Primary valve ablation and temporary vesicostomy with delayed valve ablation are alternative initial management procedures in neonates and infants with posterior urethral valves. To investigate whether initial vesicostomy followed by delayed valve ablation and simultaneous vesicostomy closure may lead to more alterations in bladder function than primary valve ablation only we retrospectively compared postoperative urodynamic findings in 2 small groups of patients.

MATERIALS AND METHODS

From 1980 to 1990, 15 male infants 19 days to 34 months old with posterior urethral valves were treated with 1 of 2 initial surgical approaches, including valve ablation only in 8 (group 1), and primary vesicostomy and delayed valve ablation associated with concomitant vesicostomy closure in 7 (group 2). Mean age at valve ablation and vesicostomy in groups 1 and 2 was 10.8 +/- 11.2 months (range 1 to 35) and 55.4 +/- 43.3 days (range 19 to 151), respectively. Average duration of vesicostomy diversion was 33.6 +/- 18.8 months (range 14 to 70). All patients underwent conventional urodynamics postoperatively using normal saline at room temperature. In groups 1 and 2 mean age at followup was 11.5 +/- 6.6 (range 5 to 16.2) and 9. 4 +/- 3.1 (range 4.10 to 14) years, respectively. Controls comprised 46 age matched males who underwent urodynamics using similar methodology.

RESULTS

Postoperative urodynamic assessment of maximum cystometric bladder capacity and the incidence of detrusor instability in each treatment group were not statistically different. In group 1 bladder capacity was significantly higher than that in controls (p <0.0001). In group 2 mean end filling detrusor pressure was increased compared with that in group 1 (29 cm. water, range 15 to 60 versus 8, range 4 to 21). Compliance was significantly lower in group 2 than in group 1 (p <0.0005). Analysis of detrusor voiding pressure at maximum flow was not significantly different in the 2 groups. We noted detrusor under activity in 1 group 1 and 2 group 2 cases. In these patients post-void residual urine volume was 8% to 66% of cystometric bladder capacity. However, only 1 of these 3 patients who required augmentation cystoplasty needed intermittent catheterization. Urodynamic patterns of outflow obstruction developed in 1 patient in each group, including urethral stricture and bladder neck obstruction. At followup we observed no difference in renal function impairment in the 2 groups.

CONCLUSIONS

Our retrospective study of rapid filling cystometry suggests that primary valve ablation for posterior urethral valves is associated with a better bladder function outcome than that in patients treated with vesicostomy and delayed valve ablation. Therefore, although cutaneous vesicostomy may be performed as initial management of posterior urethral valves, primary valve ablation is the most effective surgical option in these cases.