Urodynamic changes in patients with anterior urethral valves: before and after endoscopic valve ablation.

Purpose: To retrospectively review a series of children with anterior urethral valves (AUV), with emphasis on patterns of urodynamic change and long-term outcome of endoscopic treatment.

Patients And Methods: We reviewed the medical records of eight patients who had undergone thorough radiological and urodynamic exams before and after treatment. The diagnosis of AUV was based on radiological imaging and confirmed by urethrocystoscopy. The valves were ablated through either transurethral fulguration or resection. The upper urinary tracts were studied by renal scan and ultrasonography before and after the procedure. Bladder function was assessed urodynamically 3 months after surgery. Uroflowmetry was performed as soon as the children were toilet trained.

Results: Endoscopic ablation of AUV was successful in all cases and no surgical complications occurred. The initial symptoms resolved in all boys. VUR disappeared in two out of three patients, and five children had bladder trabeculation that was resolved after surgery. The final outcome was successful in seven patients (88%). The major urodynamic dysfunction was bladder hypercontractility that resolved following valve ablation. The mean maximum voiding detrusor pressure (P(detmax)) decreased from 213.2+/-17.9 cmH(2)O to 80.7+/-9.9 cmH(2)O, 6 months after treatment (P<0.001). None of the patients had low-compliant bladder, detrusor instability or myogenic failure. The voiding pattern in all toilet-trained patients was staccato and of an interrupted shape prior to surgery, but changed to a normal bell-shaped voiding pattern following valve ablation.

Conclusion: AUV should be considered in the differential diagnosis of patients presenting with infravesical obstruction. We recommend endoscopic valve ablation as the treatment of choice.