Injection of a bulking agent into the anal canal improves symptoms of faecal incontinence more than does a sham (placebo) treatment. The authors say this is the first time such a randomised trial comparing active and sham treatments has proven efficacy, and that the treatment is safe. The authors of the Article are Dr Wilhelm Graf, Department of Surgery, Akademiska sjukhuset, Uppsala, Sweden, and colleagues.
The prevalence of faecal incontinence is the same in men and women and ranges from around 3% in individuals aged 20-30 years to around 15% in those older than 70 years. The cause of faecal incontinence is multifactorial and not completely understood. Two recognised types of clinical incontinence exist: passive incontinence and urge incontinence. Passive incontinence (ie, leakage without notice) is related to low anal resting pressure and internal sphincter deficiency. Urge incontinence (ie, inability to withstand an urge to defecate) is often attributed to an insufficiency in external sphincter tone and activity.
While injection of a bulking agent in the anal canal is increasingly used to treat for faecal incontinence, efficacy has not been shown in a controlled trial. In this study the authors aimed to assess the efficacy of injection of dextranomer in stabilised hyaluronic acid (NASHA Dx) for treatment of faecal incontinence.
206 patients aged 18 to 75 years from the USA and Europe were randomly assigned to receive 4 injections of 1 ml of NASHA Dx in the anal canal (136 patients) or sham treatment (the same injections but no substance injected). The researchers found that, after six months, just over half (52%) patients who received NASHA Dx had a 50% or more reduction in the number of incontinence episodes, compared with less than a third (31%) who received sham treatment. There were 128 treatment-related adverse events reported in the treatment group, and 29 in the sham group. These included transient injection-site bleeding (7 in treatment group, 12 in sham) and pain (6 in treatment group, 1 in sham) Two adverse events in the treatment group were serious (1 rectal abscess and 1 prostatic abscess).
The authors conclude: "The treatment might also be used as a treatment before more invasive techniques or as an additional or adjuvant treatment if other treatments do not give adequate symptomatic relief. This treatment is easy to apply and safe. A refinement of selection criteria for patients, optimum injected dose, ideal site of injection, and long-term results might further increase the acceptance of this minimally invasive treatment."
In a linked Comment, Dr Christine Norton, Bucks New University and Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK, says that more detailed information is needed before the study could be replicated. She points to several important data not included, such as of the type of incontinence suffered (urge, passive or both), anal pressures, ultrasound appearance, or sensation, which might give clues about the mechanism of action.
Asking whether or not the study should change clinical practice, she concludes: "Maybe, but until we ask patients what they think, we cannot be sure whether a statistically significant result will actually change people's lives."
Dr Wilhelm Graf, Department of Surgery, Akademiska sjukhuset, Uppsala, Sweden. T) please complete telephone number E) wilhelm.graf@akademiska.se
Dr Christine Norton, Bucks New University and Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK. T) +44 (0) 7785 953 818 E) Christine.norton2@imperial.nhs.uk
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The Lancet