Efficacy of dextranomer in stabilised hyaluronic acid for treatment of faecal incontinence: a randomised, sham-controlled trial

Background Injection of a bulking agent in the anal canal is an increasingly used treatment for faecal incontinence, but efficacy has not been shown in a controlled trial. We aimed to assess the efficacy of injection of dextranomer in stabilised hyaluronic acid (NASHA Dx) for treatment of faecal incontinence. Methods In this randomised, double-blind, sham-controlled trial, patients aged 18-75 years from centres in USA and Europe were randomly assigned (2:1) to receive either transanal submucosal injections of NASHA Dx or sham injections. Randomisation was stratified by sex and region in blocks of six, and managed with a computer generated, real-time, web-based system. Patients and investigators were masked to assignment for 6 months when the effect on severity of faecal incontinence and quality of life was assessed with a 2-week diary and clinical assessments. The primary endpoint was response to treatment based on the number of incontinence episodes. A response to treatment was defined as a reduction in number of episodes by 50% or more. Patients in the active treatment group are still being followed up. This trial was registered with ClinicalTrials.gov, number NCT00605826. Findings 278 patients were screened for inclusion, of whom 206 were randomised assigned to receive NASHA Dx (n=136) or sham treatment (n=70). 71 patients who received NASHA Dx (52%) had a 50% or more reduction in the number of incontinence episode, compared with 22 patients who received sham treatment (31%; odds ratio 2.36, 95% CI 1.24-4.47, p=0.0089). We recorded 128 treatment-related adverse events, of which two were serious (1 rectal abscess and 1 prostatic abscess). Interpretation Anal injection of NASHA Dx is an effective treatment for faecal incontinence. 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.