Urodynamic evaluation in boys treated for posterior urethral valves

Abstract

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 tracts. The patients' ages ranged from 3 to 26 years and 27% were either adolescents or older. The urodynamic findings were categorized into 5 main patterns, although mixed patterns were also observed; (1) normal capacity and compliance with normal detrusor contractility (2/22 patients, 9.1%); (2) small-capacity, hypocompliant bladder (8/22 patients, 36.4%); (3) unstable bladder (2/22 patients, 9.1%); (4) large-capacity, hypotonic bladder with decreased detrusor contractility (2/22 patients, 9.1%); and (5) normal capacity and compliance but with decreased detrusor contractility (8/22 patients, 36.4%). More than one-half of the patients (57.1%) evacuated their bladders incompletely, and this seemed to be associated with post-treatment episodes of urinary-tract infection. The commonest symptom was daytime frequency, urgency, and leak with nocturnal enuresis, which urodynamically correlated with a small-capacity, hypocompliant or unstable bladder or to incomplete evacuation of the bladder, leading to significant post-void residue. Significant detrusor dysfunction was identified in 2 asymptomatic patients as well, emphasizing the need to perform a routine urodynamic work-up on all valve patients. Urodynamic properties seemed to be associated with age. Small, hypocompliant, and unstable bladders were almost always seen in prepubertal boys and in the first 5 years following undiversion, whereas large, hypotonic bladders with impaired contractility were seen in post-pubertal boys. While the current policy is to avoid high diversion, data in this study suggest that disorders of detrusor capacity, compliance, and contractility exist in children treated by primary valve ablation and vesicostomy and that abnormal detrusor dynamics seem to be a reflection of inherent developmental detrusor dysfunction consequent to congenital infravesical obstruction.

Best practice in the assessment of bladder function in infants

“…These patients can, instead, [Bauer et al 1984] Low bladder capacity and overactive detrusor [Lavallee et al 2013] Overactive detrusor due to an upper motor neuron lesion with occasional DSD. However, an acontractile detrusor (lower motor neuron lesion) with denervated sphincter on the EMG may be present In infant males with dilated reflux: 50% had very high bladder pressures during voiding contractions and DSD, low bladder capacity and overactive detrusor activity during filling; 25% of infant males had overdistended, large-capacity bladders with normal pressure levels at contraction and DSD, high residual urine and detrusor overactivity; 25% of infant males had reasonably normal urodynamics ] (Female infants with dilating VUR were found to have a pattern consistent with the second group of infant males) Infants and young boys: small, poorly compliant and overactive bladders Post-pubertal age group: myogenic failure [Lal et al 1999] No urodynamic-based treatment generally recommended in infancy Alpha-blockers and anticholinergics, bladderneck incision, intermittent catheterization, vesicostomy CNS, central nervous system; DSD, detrusor sphincter dyssynergism; EMG, electromyography; VUR, vesicoureteric reflux.…”

“…The urodynamic consequences of PUV are varied and may include normal bladders, overactive bladders, small capacity poorly compliant bladders and bladders with myogenic failure [Peters and Bauer, 1990]. In general, the small poorly compliant bladders and overactive bladders are seen in infants and young boys, whilst those with myogenic failure are seen in the postpubertal age group [Lal et al 1999]. The group at Bambino Gesù hospital in Rome [De Gennaro et al 2000] examined whether the urodynamic pattern from infancy to adolescence changed in a predictable manner.…”

Fetal Surgery for Posterior Urethral Valves: Long-Term Postnatal Outcomes

“…32,33 The urodynamic parameters of valve patients are known to change as the patient ages. 34 This is irrespective of the primary treatment, whether valve ablation or urinary diversion. The small number of patients in our series had similar findings to historical series of valve patients despite having had in utero relief of urethral obstruction.…”

Emerging Concepts in Transitional Care of Congenital Genitourinary Reconstructions

“…PUV patients also display a high rate of detrusor dysfunction which can manifest without symptoms [24]. Specifically, boys with PUV who present after puberty often demonstrate enlarged, hypotonic bladders with impaired contractility [24].…”