Percutaneous tibial nerve stimulation (PTNS) in females with faecal incontinence: the impact of sphincter morphology and rectal sensation on the clinical outcome

Percutaneous tibial nerve stimulation (PTNS) is an acceptable second line treatment for patients with faecal incontinence (FI) unresponsive to conservative measures. There is however a paucity of data in the literature regarding its efficacy. The aim of this prospective study was to evaluate the efficacy of PTNS in an exclusively female cohort of patients and to identify factors that may predict treatment response. A prospective cohort of female patients with FI underwent evaluation of sphincter morphology, anorectal pressures and rectal sensation as part of their physiologic assessment prior to treatment. PTNS was performed according to a specific departmental protocol. The clinical outcomes measured were: (1) Cleveland Clinic incontinence scores, (2) deferment time and (3) weekly incontinence episodes. Outcomes were compared at baseline and following treatment using appropriate statistical tests. Clinical outcomes were correlated with the results of the anorectal physiology testing (i.e. sphincter morphology, rectal sensation). Eighty-eight female patients with a mean age of 58.0 +/- 13.6 years were included in the analysis. FI was predominantly a late consequence of obstetric injury. The mean incontinence score improved from 12.2 +/- 4.0 at baseline to 9.1 +/- 4.6 following treatment (p < 0.0001). Statistically significant improvements were also seen in the median deferment time and median number of weekly incontinence episodes. Sphincter damage and altered rectal sensation did not appear to influence the outcomes. PTNS is an effective treatment in female patients with FI. Improvements in clinical outcomes were independent of damage to the anal sphincter complex in patients with normal rectal sensation.