Sacral neuromodulation compared with injection of bulking agents for faecal incontinence following obstetric anal sphincter injury - a randomized controlled trial.
BACKGROUND Fecal incontinence and constipation are disabling conditions that reduce quality of life. If conservative treatment fails, one option is sacral nerve stimulation (SNS), a minimally invasive technique allowing modulation of the nerves and muscles of the pelvic floor and hindgut. OBJECTIVES To assess the effects of SNS for fecal incontinence and constipation in adults. SEARCH STRATEGY We searched the Cochrane Incontinence Group Specialized Trials Register (searched 24 April 2007) and the reference lists of relevant articles. SELECTION CRITERIA All randomized or quasi-randomized trials assessing the effects of SNS for fecal incontinence or constipation in adults. DATA COLLECTION AND ANALYSIS Two review authors independently screened the search results, assessed the methodological quality of the included studies, and undertook data extraction. MAIN RESULTS Three crossover studies were included. Two, enrolling 34 (Leroi) and two participants (Vaizey), assessed the effects of SNS for fecal incontinence, and one (Kenefick), enrolling two participants, assessed SNS for constipation. In the study by Leroi, following the crossover period, participants, while still blinded, chose the period of stimulation they had preferred. Outcomes at different time points were reported separately for 19 participants who preferred the "on" and five who preferred the "off" period. For the group of 19, the median (range) episodes of fecal incontinence per week fell from 1.7 (0-9) during the "off" period to 0.7 (0-5) during the "on" period; for the group of five, however, the median (range) rose from 1.7 (0-11) during the "off" period compared with 3.7 (0-11) during the "on" period. Vaizey reported an average of six, and one, episodes of fecal incontinence per week during the "off" and "on" periods, respectively. Leroi reported that four of 27 participants experienced an adverse event resulting in removal of the stimulator; Vaizey did not report adverse events. For SNS for constipation, during the "off" crossover period the participants experienced an average of two bowel movements per week, compared with five during the "on" period. Abdominal pain and bloating occurred 79% of the time during the "off" period compared with 33% during the "on" period. No adverse events occurred. AUTHORS' CONCLUSIONS The very limited evidence from the included studies suggests that SNS can improve continence in selected people with fecal incontinence, and reduce symptoms in selected people with constipation. However, temporary, percutaneous stimulation for a 2-3-week period does not always successfully identify those for whom a permanent implant will be beneficial. Larger, good quality randomized crossover trials are needed to allow the effects of SNS for these conditions to be assessed with more certainty.