Fourteen studies (n=420 patients, range 10 to 73) were included in the review: one randomised controlled trial (RCT) and thirteen case series. The RCT was reported to use concealed allocation, and blinded assessment of incontinence scoring. Of the case series, one scored 4 points, five scored 3 points, five scored 2 points and two scored 1 point. Follow up ranged from five weeks to 24 months.
Faecal incontinence (14 studies): One RCT (n=44 patients) reported no significant differences between PTQ injections and placebo at three months post-treatment. Eleven out of thirteen case-series studies reported improvement in incontinence scores at final follow-up (mean follow-up ranging from 1.5 months to 20.8 months). In sub-group analyses, no differences were reported between groups for PTQ and Durasphere injections for longer or shorter follow-up periods.
Anal manometry (nine case series): Two out of five case series using PTQ bulking agent reported a significant increase in maximum squeeze pressure, but not in maximum resting pressure. One of three case series using Durasphere injections reported significant increases in maximum squeeze pressure and maximum resting pressure. One case series reported no significant differences for either maximum squeeze pressure or maximum resting pressure using Contigen.
Quality of life (12 studies): One RCT (n=44 patients) found no statistically significant differences between PTQ injection and placebo. Seven out of 11 case series reported a statistically significant improvement in quality of life.
Adverse events and safety: Fifty-two adverse events were reported across the studies; most of these were considered minor. More serious events were persistent anal discomfort (n=1 patient), infection requiring drainage (n=1 patient), pain during defaecation (n=1 patient), and significant pain during injection (n=1 patient). Other events included anal bleeding, soiling, leakage and dermatitis. Migration of the injectable bulking agent was reported in 14 patients. Two patients reported leakage with stool.