Periurethral injection therapy for urinary incontinence in women

Stress urinary incontinence is a common, troublesome symptom amongst adult women. Periurethral injection of bulking agents is a surgical procedure used for the treatment of urinary incontinence.

To assess the effects of periurethral injection therapy in the treatment of urinary incontinence in women.

We searched the Cochrane Incontinence Group trials register (February 2003), MEDLINE (January 1996 to January 2003), PREMEDLINE (7 February 2003) and the reference lists of relevant articles. Date of the most recent searches: February 2003.

All randomised or quasi-randomised controlled trials of treatment for urinary incontinence, in which at least one management arm involved periurethral injection therapy.

Two reviewers independently assessed methodological quality of each study using explicit criteria. Data extraction was undertaken independently using a standard form and clarification concerning possible unreported data sought directly from the investigators.

We identified seven trials that met the inclusion criteria. The limited data available prevented meta-analysis. Injection of autologous fat was compared to placebo in a study of 68 women which was terminated early because of safety concerns. No differences in subjective or objective outcome were found in the two groups. No studies were found comparing injection therapy with conservative treatment. The single study that compared injection with a variety of surgical management in 133 women found no significant difference in subjective outcome but did note significantly better objective outcome in the surgical group. The four studies that compared different agents found that silicone particles and carbon spheres gave improvement at 12 months equivalent to collagen. A comparison of paraurethral and transurethral methods of delivery of the bulking agent found similar outcome but a higher rate of early complications in the paraurethral group.

Data from the available randomised trials suggest, but do not prove, that periurethral injection of established manufactured bulking agents results in subjective and objective short term improvement of symptomatic female stress urinary incontinence in adults. Future recommendation as a first line treatment would require evidence of patient benefit and cost-effectiveness from randomised trials involving placebo and conservative treatment arms. Future studies should also record long-term outcome and monitor for delayed particle migration. Injection therapy is probably inferior to surgery but a long term comparative study against a single standard procedure (Burch colposuspension) is required to prove this. It is recommended that phase III studies of newer agents will not be worthwhile until the aforementioned trials have been performed and a rationale for the use of injection therapy decided. For women with extensive co-morbidity precluding anaesthesia, injection therapy may represent a useful option for relief of symptoms for a 12 month period although 2 or 3 injections are likely to be required to achieve a satisfactory result.