Systematic review of tibial nerve stimulation to treat faecal incontinence.

BACKGROUND: Two forms of tibial nerve stimulation are used to treat faecal incontinence (FI): percutaneous (PTNS) and transcutaneous (TTNS) tibial nerve stimulation. This article critically appraises the literature on both procedures.
METHODS: A systematic review was performed adhering to the PRISMA framework. A comprehensive literature search was conducted, with systematic methodological quality assessment and data extraction. Summary measures for individual outcome variables are reported.
RESULTS: Twelve articles met eligibility criteria; six related to PTNS, five to TTNS, and one to both procedures. These included ten case series and two randomized clinical trials (RCTs). Case series were evaluated using the National Institute for Health and Care Excellence quality assessment for case series, scoring 3-6 of 8. RCTs were evaluated using the Jadad score, scoring 4 of a possible 5 marks, and the Cochrane Collaboration bias assessment tool. From one RCT and case series reports, the success rate of PTNS, based on the proportion of patients who achieved a reduction in weekly FI episodes of at least 50 per cent, was 63-82 per cent, and that of TTNS was 0-45 per cent. In an RCT of TTNS versus sham, no patient had a reduction in weekly FI episodes of 50 per cent or more, whereas in an RCT of PTNS versus TTNS versus sham, 82 per cent of patients undergoing PTNS, 45 per cent of those having TTNS, and 13 per cent of patients in the sham group had treatment success.
CONCLUSION: PTNS and TTNS result in significant improvements in some outcome measures; however, TTNS was not superior to sham stimulation in a large, adequately powered, RCT. As no adequate RCT of PTNS versus sham has been conducted, conclusions cannot be drawn regarding this treatment.