[Urethral valves. Fate of the bladder and upper urinary tract].

Posterior urethral valve is a condition that leads to characteristic changes in the bladder and upper tracts. The bladder develops hypertrophic changes including muscular hypertrophy, dilatation of the prostatic urethra (keyhole appearance), and progressive hydroureteronephrosis. The voiding cystourethrogram confirms the diagnosis and documents vesicoureteral reflux and accompanying bladder changes. The follow-up of the serum creatinine level is a parameter for renal recovery. In our opinion, primary endoscopic ablation of the valves followed by a wait-and-see attitude is the most efficacious management of posterior urethral valves. The development of the bladder function is controlled by ultrasound and voiding cystourethrogram. Urodynamics provide a formal and objective means of assessing bladder function, but should be carefully applied in infants. Valve ablation in a neonate with significant reflux and a markedly trabeculated bladder can remodel itself remarkably within the 1st year of life. The persistence of hydronephrosis, bladder wall thickening and trabeculation, and persistent elevation of serum creatinine can all be harbingers that a degree of bladder outlet obstruction persists and one needs to rule out a persistent anatomic obstruction. At what point a functional obstruction occurs and which management is reasonable are still issues of debate and require the vigilance of a pediatric urologist to sort out. Dysfunctions of the bladder such as hyperreflexia, hypertonic, small capacity bladder, sphincter incompetence and/or myogenic failure should be adequately treated.