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.

Funding: Q-Med AB.