Randomized clinical trial of percutaneous tibial nerve stimulation versus sham electrical stimulation in patients with faecal incontinence

Background: The aim was to assess the effects of percutaneous tibial nerve stimulation (PTNS) in the treatment of faecal incontinence (FI) by means of an RCT. Methods: Patients aged over 18 years with FI were included in a multi centre, single-blinded RCT. The primary end point was reduction in the median or mean number of FI episodes per week. Secondary end points were changes in measures of FI severity, and disease-specific and generic quality of life. Outcomes were compared between PTNS and sham stimulation after 9 weeks of treatment. Results: A higher proportion of patients in the PTNS (13 of 29) than in the sham (6 of 30) group showed a reduction of at least 50 per cent in the median number of FI episodes/week (incidence rate ratio (IRR) 2.40, 95 per cent c.i. 1.10 to 5. 24; P = 0.028), but not in the mean number of episodes/week (10 of 29 versus 8 of 30; IRR 1.42, 0.69 to 2.92; P = 0.347). The absolute median number of FI episodes per week decreased in the PTNS but not in the sham group (IRR 0. 66, 0.44 to 0.98; P = 0.041), as did the mean number (IRR 0.65 (0.45 to 0.97); P = 0.034). Scores on the Cleveland Clinic Florida faecal incontinence scale decreased significantly in both groups, but more steeply in the PTNS group (mean difference -1.3, 95 per cent c.i. -2.6 to 0.0; P = 0.049). The aggregated mental component score of Short Form 36 improved in the PTNS but not in the sham group (mean difference 5.1, 0.5 to 9.6; P = 0.028). Conclusion: PTNS may offer a small advantage in the clinical management of FI that is insufficiently responsive to conservative treatment. The key challenge will be to identify patients who may benefit most from this minimally invasive surgical procedure.