Sacral nerve stimulation for treatment of refractory urinary urge incontinence. Sacral Nerve Stimulation Study Group. Randomized trial of percutaneous tibial nerve stimulation versus extended-release tolterodine: results from the overactive bladder innovative therapy trial. Efficacy of sacral nerve stimulation for urinary retention: results 18 months after implantation. Double-blind crossover study of sacral nerve stimulation for fecal incontinence.
A prospective, randomized study was performed to evaluate sacral nerve stimulation for the treatment of refractory urinary urge incontinence.
                Primary outcome variables were obtained from voiding diaries. After baseline evaluation candidates who satisfied inclusion criteria were enrolled into the study. Test stimulation results determined eligibility for randomization into a stimulation (treatment) or delay (control) group. The stimulation group included 34 patients who underwent implantation and were followed for 6 months. The delay group comprised 42 patients who received standard medical therapy for 6 months and then were offered implantation. The stimulation group completed a therapy evaluation test (on versus off) after 6 months.
                At 6 months the number of daily incontinence episodes, severity of episodes and absorbent pads or diapers replaced daily due to incontinence were significantly reduced in the stimulation compared to the delay group (all p<0.0001). Of the 34 stimulation group patients 16 (47%) were completely dry and an additional 10 (29%) demonstrated a greater than 50% reduction in incontinence episodes 6 months after implantation. Efficacy appeared to be sustained for 18 months. During the therapy evaluation test the group returned to baseline levels of incontinence when stimulation was inactivated. Urodynamic testing confirmed that sacral nerve stimulation did not adversely affect voiding function. Complications included implantable pulse generator site pain in 15.9% of the patients, implant site pain in 19.1% and lead migration in 7.0%. Surgical revision was required in 32.5% of patients with implants to resolve a complication. There were no reports of permanent injury or nerve damage.
                Sacral nerve stimulation is safe and effective in treating refractory urinary urge incontinence. The Overactive Bladder Innovative Therapy trial was a randomized, multicenter, controlled study that compared the effectiveness of percutaneous tibial nerve stimulation to extended-release tolterodine. The reduction in overactive bladder symptoms along with global response assessments was evaluated.
                A total of 100 adults with urinary frequency were randomized 1:1 to 12 weeks of treatment with weekly percutaneous tibial nerve stimulation or to 4 mg daily extended-release tolterodine. Voiding diaries and an overactive bladder questionnaire were completed at baseline and at the end of therapy to compare 24-hour voiding frequency, urinary urge incontinence episodes, voids causing waking, volume voided, urgency episodes and quality of life indices. Global response assessments were completed by subjects and investigators after 12 weeks of therapy.
                The global response assessment demonstrated that subject assessment of overactive bladder symptoms compared to baseline was statistically significant in the percutaneous tibial nerve stimulation arm with 79.5% reporting cure or improvement compared to 54.8% of subjects on tolterodine (p = 0.01). Assessments by investigators were similar but did not reach statistical significance (p = 0.05). After 12 weeks of therapy objective measures improved similarly in both groups for reductions in urinary frequency, urge urinary incontinence episodes, urge severity and nighttime voids, as well as for improvement in voided volume. There were no serious adverse events or device malfunctions.
                This multicenter, randomized trial demonstrates that percutaneous tibial nerve stimulation is safe with statistically significant improvements in patient assessment of overactive bladder symptoms, and with objective effectiveness comparable to that of pharmacotherapy. Percutaneous tibial nerve stimulation may be considered a clinically significant alternative therapy for overactive bladder. We investigate the efficacy of sacral neurostimulation in patients with idiopathic urinary retention in a prospective, randomized multicenter trial.
                A total of 177 patients with urinary retention refractory to standard therapy were enrolled in the study. Greater than 50% improvement in baseline voiding symptoms during a 3 to 7-day percutaneous test stimulation qualified a patient for surgical implantation of an InterStim parallel system. Of the patients who qualified for implantation 37 were randomly assigned to a treatment and 31 to a control group. Patients in the treatment group underwent early surgical implantation of the sacral nerve stimulation system, while implantation was delayed in the control group for 6 months. Followup evaluations, including voiding diary analysis and temporary deactivation of the stimulator at 6 months, were conducted at 1, 3, 6, 12 and 18 months after implantation in the treatment group, and after 3 and 6 months in the control group.
                Compared to the control group, patients implanted with the InterStim system had statistically and clinically significant reductions in the catheter volume per catheterization (p <0.0001). Of the patients treated with implants 69% eliminated catheterization at 6 months and an additional 14% had a 50% or greater reduction in catheter volume per catheterization. Therefore, successful results were achieved in 83% of the implant group with retention compared to 9% of the control group at 6 months. Temporary inactivation of sacral nerve stimulation therapy resulted in a significant increase in residual volumes (p <0.0001) but effectiveness of sacral nerve stimulation was sustained through 18 months after implant.
                Results of this prospective, randomized clinical study demonstrate that sacral nerve stimulation is effective for restoring voiding in patients with retention who are refractory to other forms of treatment. 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.
In spite of methodological problems, it would appear that some people benefit from implants which provide continuous nerve stimulation. More research is needed on the best way to improve patient selection, carry out the implant, and to find why so many fail. The effectiveness of implants should be tested against other interventions, particularly in people with an overactive bladder.