BLADDER DYSFUNCTION IN BOYS WITH POSTERIOR URETHRAL VALVES

Posterior urethral valve (PUV) is a congenital urethral obstruction on ly affecting boys. As a result of the obstruction in fetal life, these boys often have a persisting bladder dysfunction, which is one of the main causes of the late onset renal failure seen in 1/3 of the boys a nd is also responsible for the delayed achievement of continence. The aim of this study was to characterize the bladder dysfunction from inf ancy through childhood and adolescence in buys with neonatally diagnos ed PUV with the intention of designing a bladder treatment regimen sta rting in infancy: Paper I: 16 infant boys with PUV were followed with repeated standard cystometries. At presentation the bladders were hype rcontractile with low capacity, During the first three years of life t he urodynamic pattern changed, with vanishing hypercontractility and i ncreasing bladder capacity, even though the instability remained uncha nged. Paper II: 12 boys were followed with standard cystometries betwe en 4 and 12 years of age and compared with a group of 6 postpubertal b oys with PUV. The urodynamic pattern continued to change, with decreas ing instability and contractility, A major problem was emptying diffic ulties. Paper III: The voiding pattern during the day versus the night in 10 incontinent and 6 continent boys with PUV was evaluated by long -term natural filling cystometry. The voiding pattern, with small freq uent voidings during the day and few or no voidings during the night w ith high bladder volumes in the morning, could be explained by pronoun ced instability during the day whereas the bladders were stable during the night. Paper IV: The method of ''4 hour voiding observation'' was presented as a non-invasive method for basic assessment of bladder fu nction in non-toilet trained children and the voiding pattern in 43 he althy infants was demonstrated. Paper V: The voiding pattern, with spe cial attention to emptying difficulties, in 25 small children with PUV compared to healthy children of corresponding age, was evaluated with the ''4 hour voiding observation''. Conclusions: Boys with PUV have a bladder dysfunction with a changing urodynamic pattern over time with decreasing contractility and instability, In small boys die instabili ty was pronounced during daytime while during the night the bladders w ere mainly stable. Most boys with PUV and bladder dysfunction end up w ith a decompensated bladder, A major problem was bladder emptying diff iculties. The ''4 hour voiding observation'' is an excellent non-invas ive method of identifying those patients in need of early bladder trea tment, i.e. with clean intermittent catheterisation.