MANAGEMENT OF POSTERIOR URETHRAL VALVES ON THE BASIS OF URODYNAMIC FINDINGS

Purpose: Abnormal urodynamic findings are common in boys with a histor y of posterior urethral valves. However, to our knowledge there are fe w reports on the results of treating these abnormal findings. We analy zed the treatment of abnormal urodynamic parameters and its outcome in 21 boys who underwent valve ablation. Materials and Methods: After va lve ablation multichannel urodynamic studies were performed in 31 boys , including 21 in whom studies were done before and after therapy was started for abnormal parameters. Detrusor instability and impaired bla dder compliance were treated with anticholinergics or augmentation cys toplasty, and impaired detrusor contractility was managed with clean i ntermittent catheterization. Results: Before therapy 17 of 21 boys had impaired compliance and detrusor instability, 2 had impaired complian ce without instability and 2 had instability alone. After treatment 8 boys had impaired compliance and 4 had detrusor instability. After ant icholinergics were initiated new onset myogenic failure in 2 boys nece ssitated clean intermittent catheterization. Of the 13 patients who pr esented with urinary incontinence 10 became dry and 3 had improvement with therapy. Vesicoureteral reflux in 10 boys at the time of the init ial urodynamic study resolved in 7 with anticholinergic medication and in 1 after clean intermittent catheterization was begun for severely impaired compliance. All 21 boys were treated with anticholinergics an d 2 were ultimately treated with augmentation cystoplasty. Clean inter mittent catheterization was also instituted in 5 patients, including t he 2 who required clean intermittent catheterization after myogenic fa ilure developed. Five boys with high voiding pressures were found to h ave outlet obstruction due to residual valve tissue in 2, bladder neck obstruction in 2 and urethral stricture in 1 despite normal flow rate s in 2. Conclusions: Urodynamic studies are helpful in guiding therapy in boys after valve ablation. Anticholinergic therapy can improve com pliance, decrease detrusor instability, improve continence and elimina te vesicoureteral reflux in the majority of boys, although there is an associated risk of myogenic failure. Flow rates and fluoroscopic void ing studies are often unable to detect outlet obstruction and must be obtained in conjunction with voiding pressure measurements to make thi s diagnosis.