Double-blind crossover study of sacral nerve stimulation for fecal incontinence. Efficacy of sacral nerve stimulation for fecal incontinence: results of a multicenter double-blind crossover study. Sacral nerve stimulation is more effective than optimal medical therapy for severe fecal incontinence: a randomized, controlled study.
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.
                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.
                There was a dramatic difference between the number and severity of episodes of incontinence when the stimulator was turned on vs. turned off (Patient 1, 20 vs. 2 episodes; Patient 2, 4 vs. 0 episodes; off vs. on). There was an increase in squeeze pressure (Patient 1, 70 vs. 100 cm H2O; Patient 2, 60 vs. 90 cm H2O; off vs. on), with moderate increases in resting pressure and rectal threshold and urge volumes. Quality-of-life measurements showed a marked improvement prestimulation vs. nine months after permanent stimulation.
                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. This is the first double-blind multicenter study examining the effectiveness of sacral nerve stimulation in a significant number of fecally incontinent patients.
                A total of 34 consecutive patients (31 women), median age 57 years (range, 33-73 years), underwent sacral nerve stimulation for fecal incontinence. After implantation, 27 of 34 patients were randomized in a double-blind crossover design to stimulation ON or OFF for 1-month periods. While still blinded, the patients chose the period of stimulation (ON or OFF) that they had preferred. The mode of stimulation corresponding to the selected period was continued for 3 months (final period). Outcome measures were frequency of fecal incontinence and urgency episodes, delay in postponing defecation, score severity, feeling of improvement, preference for ON or OFF, quality of life, and manometric measurements.
                In the crossover portion of the study, the self-reported frequency of fecal incontinence episodes was significantly reduced during the ON versus the OFF period (P = 0.03), and this symptomatic improvement was consistent: 1) with the patients feeling of greater improvement during the ON versus OFF period (P = 0.02); 2) with the significant preference of patients (P = 0.02) for the ON versus OFF period. In the final period of the study, the frequency of fecal incontinence episodes decreased significantly (P = 0.005) in patients with the stimulator ON. The ability to postpone defecation (P = 0.01), the score for symptom severity (P = 0.0004), and the quality of life (P < 0.05) as well as anal sphincter function significantly improved.
                The significant improvement in FI during the ON versus OFF period indicated that the clinical benefit of sacral nerve stimulation was not due to placebo. This randomized study was designed to compare the effect of sacral neuromodulation with optimal medical therapy in patients with severe fecal incontinence.
                Patients (aged 39-86 years) with severe fecal incontinence were randomized to have sacral nerve stimulation (SNS group; n = 60) or best supportive therapy (control; n = 60), which consisted of pelvic floor exercises, bulking agent, and dietary manipulation. Full assessment included endoanal ultrasound, anorectal physiology, two-week bowel diary, and fecal incontinence quality of life index. The follow-up duration was 12 months.
                The sacral nerve stimulation group was similar to the control group with regard to gender (F:M = 11:1 vs. 14:1) and age (mean, 63.9 vs. 63 years). The incidence of a defect of < or = 120 degrees of the external anal sphincter and pudendal neuropathy was similar between the groups. Trial screening improved incontinent episodes by more than 50 percent in 54 patients (90 percent). Full-stage sacral nerve stimulation was performed in 53 of these 54 "successful" patients. There were no septic complications. With sacral nerve stimulation, mean incontinent episodes per week decreased from 9.5 to 3.1 (P < 0.0001) and mean incontinent days per week from 3.3 to 1 (P < 0.0001). Perfect continence was accomplished in 25 patients (47.2 percent). In the sacral nerve stimulation group, there was a significant (P < 0.0001) improvement in fecal incontinence quality of life index in all four domains. By contrast, there was no significant improvement in fecal continence and the fecal incontinence quality of life scores in the control group.
                Sacral neuromodulation significantly improved the outcome in patients with severe fecal incontinence compared with the control group undergoing optimal medical therapy.
The very limited evidence from the included studies suggests that SNS can improve continence in selected people with faecal incontinence, and reduce symptoms in selected people with constipation. However temporary, percutaneous stimulation for a two-to-three week period does not always successfully identify those for whom a permanent implant will be beneficial. Larger, good quality randomised crossover trials are needed to allow the effects of SNS for these conditions to be assessed with more certainty.