Comparison of bulking agents in the treatment of fecal incontinence: a prospective randomized clinical trial

We sought to compare two synthetic injectable bulking agents, with known efficacy (PTQ™: a silicone biomaterial and Durasphere^®: pyrolytic carbon-coated beads), in the form of a randomised clinical trial.

Circumferential injection of either agent was performed under local anesthesia and sedation as a day-case procedure. The primary outcome measure was the Wexner incontinence scale. Secondary measures were the short-form 36 (SF-36) quality of life assessment and manometry (maximum resting and squeeze pressures). Follow-up was at 6 weeks, 6 and 12 months.

Thirty-five patients were randomised, 17 to PTQ^® and 18 to Durasphere^®. Early closure of the trial occurred, due to the removal of the agent PTQ^®, from the Australian Pharmaceutical Benefits scheme. Wexner incontinence scores were significantly better than baseline, in both groups, at 6 weeks and 6 months (P < 0.05), although the improvements were not significant at 12 months. There was no significant improvement for either agent, from baseline, in mean SF-36 scores at any follow-up sessions. There was no significant difference between the two bulking agents, with regard to both Wexner and SF-36 scores, at any of the follow-up sessions. Complications occurred in one patient in the PTQ group (perianal abscess) and did not occur in any of the patients in the Durasphere group.

This trial appears to show that both synthetic agents PTQ^® and Durasphere^® are effective and safe, although long-term improvement is limited. In this trial, there appears to be no difference in efficacy between the two agents, over a 12-month follow-up period.