Percutaneous tibial nerve stimulation (pTNS): success rate and the role of rectal capacity

Percutaneous tibial nerve stimulation (pTNS) was originally developed to treat urinary incontinence. Recently, some case series have also documented its success in the treatment of fecal incontinence. Nevertheless, the mechanism underlying this effect remains unknown but may be related to changes in rectal capacity. The aim of this study was to investigate the success of pTNS for the treatment of fecal urge incontinence and assess the influence of rectal capacity on treatment efficacy.

All patients undergoing pTNS for fecal incontinence between July 2009 and March 2014 were enrolled in a prospective, observational study consisting of a therapeutic regimen that lasted 9 months. Therapy success was defined as a reduction in the CCI (Cleveland Clinic incontinence) score of ≥50% and patient-reported success. Furthermore, quality of life (Rockwood's scale) and changes in anorectal physiology were recorded.

Fifty-seven patients with fecal urge incontinence were eligible, nine of whom were excluded. The success rate was 72.5%. Incontinence events and urge symptoms were significantly reduced after 3 months and at the end of therapy. The median CCI score decreased from 12 to 4 (P < 0.0001), and the quality of life was significantly improved. However, rectal capacity was not significantly related to treatment success before or after therapy. No adverse events were observed.

These results demonstrate that pTNS can improve the symptoms and quality of life of patients with fecal urge incontinence. However, the study fails to demonstrate a correlation between treatment success and changes in rectal capacity.