Double-blind crossover study of sacral nerve stimulation for fecal incontinence

Abstract

PURPOSE: Patients with fecal incontinence not amenable to simple repair may have to undergo major reconstructive surgery or resort to a stoma. Sacral nerve stimulation is an alternative approach that may diminish incontinence by altering sphincter and rectal motor function. This study is the first double-blind trial examining the effectiveness of this therapy. METHODS: Two patients with passive fecal incontinence who had been implanted for nine months with a permanent sacral nerve stimulator and electrode were studied using fecal incontinence diaries, anorectal physiological tests, and quality-of-life assessments (SF-36 health survey). The trial period consisted of two two-week periods, with the stimulator turned on for two weeks and off for two weeks. The main investigator and the patients were blinded to the status of the stimulator. RESULTS: There was a dramatic difference between the number and severity of episodes of incontinence when the stimulator was turned onvs. turned off (Patient 1, 20vs. 2 episodes; Patient 2, 4vs. 0 episodes; offvs. on). There was an increase in squeeze pressure (Patient 1, 70vs. 100 cm H₂O; Patient 2, 60vs. 90 cm H₂O; offvs. on), with moderate increases in resting pressure and rectal threshold and urge volumes. Quality-of-life measurements showed a marked improvement prestimulationvs. nine months after permanent stimulation. CONCLUSIONS: There is a marked, unequivocal improvement in symptoms of fecal incontinence with sacral nerve stimulation shown in this double-blind crossover trial. Sacral nerve stimulation improves the quality of life in selected patients with fecal incontinence.