Endourethral injection of bulking agents for urinary incontinence in children

To assess the early and late outcome of endourethral injection with bulking agents in children with urinary incontinence (a neuropathic bladder or exstrophy-epispadias complex), by reviewing our experience over a 5-year period.

The records of 15 children (10 boys) were reviewed retrospectively; 10 had spina bifida and a neurogenic bladder, four had a neurogenic bladder from other causes and one had epispadias. All children had a stable low-pressure detrusor and a compliant bladder with sphincteric weakness on preoperative urodynamic testing. Four children had undergone previous enterocystoplasty with a Mitrofanoff stoma, with concomitant urethral lengthening in two and a Goretex trade mark bladder neck sling in two. Three children voided spontaneously while 12 depended on intermittent catheterization. The agent was injected under general anaesthesia in all patients but one, with an endourethral submucosal injection of the bulking agent into four or more points at the junction of the bladder neck and proximal urethra, aiming to obtain visual occlusion of the urethra. The median (range) number of injections was 2 (1-3); five children had one injection, seven had two and three had three. There were no procedure-related complications and most were day-case procedures. Initially PTFE paste was used as the bulking agent, being replaced by bovine collagen or polydimethylsiloxane in the latter half of the series.

At a median (range) follow-up of 28 (11-65) months three children were completely dry after a single injection; there was no change in four and a short-term improvement (median 25 months, range 4 days to 37 months) in eight. After this period all children deteriorated to their original incontinence grade; hence the overall cure rate was three of 15.

This experience with a long-term follow-up differs from previously reported high success rates for the endourethral injection of bulking agents for urinary incontinence in children. Despite a short-term benefit, in the long-term this technique was unreliable and often ineffective. Patients and their carers should be given a realistic and guarded prognosis.