The Urodynamic Consequences of Posterior Urethral Valves

Abstract

We evaluated urodynamically 41 patients with posterior urethral valves because of signs or symptoms of incontinence (35), frequency (3), hydronephrosis (2) and infection (1). Findings included normal urodynamic evaluations in 3 patients, 2 had high voiding pressures secondary to outlet resistance and 1 had incontinence on the basis of external urethral sphincter damage. In the remainder 3 patterns of bladder dysfunction were identified. Myogenic failure with overflow incontinence occurred in 14 patients. In this group clean intermittent catheterization or Valsalva's voiding was used for emptying. Hyperreflexic bladders were seen in 10 patients. Pharmacological suppression of instability was effective in 5 of 7 patients treated; 1 required bladder augmentation. Eleven children had a small capacity bladder and poor compliance. Post-void residuals were low and these bladders were generally but not always stable. Pharmacological bladder relaxation was successful in 3 patients, 3 underwent augmentation, 1 did well with alpha-agonists and followup is unavailable on the other 4. These 3 patterns of bladder dysfunction represent an overlapping constellation of residual urodynamic abnormalities due to previous bladder outlet obstruction. Individual patients may show facets of several types of dysfunction associated with 1 predominant pattern.

Guinea pig as an animal model for the study of urinary bladder function in the normal and obstructed state

“…These studies further suggested that identical degrees of obstruction produced several different patterns of voiding dysfunction, each of which was associated with varying degrees of bladder weight increase. [32] and are also familiar to clinicians caring for men with prostatic obstruction [3,4]. Since the smallest degree of weight gain was found in association with high pressure voiding and the largest degree of weight gain was found in association with instability and decompensation, the results suggested to us that the response of the bladder to outflow obstruction might proceed along a continuum, characterized in its initial stages by high pressure voiding, and in later stages by instability and eventually decompensation.…”

Posterior urethral valves

“…The description of the valve bladder syndrome by Peters is useful in following these patients long term [23]. Of course, all children with PUV are different and do not necessarily follow any schedule in terms of deteriorating bladder function, but it is clear that different patterns of bladder pathology are seen specifically in children with PUV.…”

Micturition pattern in young boys with posterior urethral valves—A pilot study in small boys who are potty-trained from infancy

“…Even if bladder dysfunction due to valves can show different patterns [5] in response to the grade of detrusor hypertrophy induced by the obstruction, it has been suggested that the pattern in infancy and first years of life is characterized by hyper-contractility. This is recognized as over-activity during filling with frequent voidings and low bladder capacity [6].…”