Background: Faecal incontinence is a complex and distressing condition with significant medical and social implications. Injection of perianal bulking agents has been used to treat the symptoms of passive faecal incontinence. However, various different agents have been used without a standardised technique and the supposed benefit of the treatment is largely pragmatic with a limited clinical research base.
Objectives: To determine the effectiveness of perianal injection of bulking agents for the treatment of faecal incontinence in adults.
Search strategy: We searched the Cochrane Incontinence Group Specialised Register of trials (searched 10 June 2009), ZETOC (searched 18 July 2009), clinical trials registries (searched 18 July 2009) and the reference lists of relevant articles.
Selection criteria: All randomised or quasi-randomised controlled trials comparing use of injectable bulking agents for faecal incontinence with any alternative treatments or placebo were reviewed to evaluate the therapeutic effects. Case-control and cohort studies were also reviewed to assess risks and complications associated with the treatment.
Data collection and analysis: Two reviewers assessed the methodological quality of eligible trials and independently extracted data from included trials using a range of pre-specified outcome measures.
Main results: Four eligible randomised trials were identified with a total of 176 patients. All trials but one were at an uncertain or high risk of bias. Most trials reported a short term benefit from injections regardless of the material used as outcome measures improved over time. A silicone biomaterial (PTQ), was shown to provide some advantages and was safer in treating faecal incontinence than carbon-coated beads (Durasphere(R)) in the short term. Similarly, there were short term benefits from injections delivered under ultrasound guidance compared with digital guidance. However, PTQ did not demonstrate obvious clinical benefit compared to control injection of normal saline. No long term evidence on outcomes was available and further conclusions were not warranted from the available data.
Authors' conclusions: A definitive conclusion cannot be drawn regarding the effectiveness of perianal injection of bulking agents for faecal incontinence due to the limited number of identified trials together with methodological weaknesses. Within the available data, however, we found no reliable evidence for effectiveness of one treatment over another in improving faecal incontinence. Larger well-designed trials with adequate numbers of subjects using reliable validated outcome measures are needed to allow definitive assessment of the treatment for both effectiveness and safety.