Urodynamic evaluation in boys treated for posterior urethral valves

This study describes the urodynamic findings in 22 patients with posterior urethral valves and discusses their association with urinary incontinence, age, mode of primary treatment, renal function, and changes in the upper tr acts. The patients' ages ranged from 3 to 26 years and 27% were either adol escents or older. The urodynamic findings were categorized into 5 main patt erns, although mixed patterns were also observed; (1) normal capacity and c ompliance with normal detrusor contractility (2/22 patients, 9.1%); (2) sma ll-capacity, hypocompliant bladder (8/22 patients, 36.4%); (3) unstable bla dder (2/22 patients, 9.1%); (4) large-capacity, hypotonic bladder with decr eased detrusor contractility (2/22 patients, 9.1%); and (5) normal capacity and compliance but with decreased detrusor contractility (8/22 patients, 3 6.4%). More than one-half of the patients (57.1%) evacuated their bladders incompletely, and this seemed to be associated with posttreatment episodes of urinary-tract infection. The commonest symptom was daytime frequency, ur gency, and leak with nocturnal enuresis, which urodynamically correlated wi th a small-capacity, hypocompliant or unstable bladder or to incomplete eva cuation of the bladder, leading to significant post-void residue. Significa nt detrusor dysfunction was identified in 2 asymptomatic patients as well, emphasizing the need to perform a routine urodynamic work-up on all valve p atients. Urodynamic properties seemed to be associated with age. Small, hyp ocompliant, and unstable bladders were almost always seen in prepubertal bo ys and in the first 5 years following undiversion, whereas large, hypotonic bladders with impaired contractility were seen in post-pubertal boys. Whil e the current policy is to avoid high diversion, data in this study suggest that disorders of detrusor capacity, compliance, and contractility exist i n children treated by primary valve ablation and vesicostomy and that abnor mal detrusor dynamics seem to be a reflection of inherent developmental det rusor dysfunction consequent to congenital infravesical obstruction.