MPDescriptionPub
Pelvic floor stimulation has been proposed as a nonsurgical treatment option for the treatment of urinary and fecal incontinence. This approach involves either non-implantable electrical stimulation (NIES) of the pelvic floor musculature or extracorporeal magnetic pelvic floor stimulation (MPFS). The intent of these interventions is to stimulate the pudendal nerve to activate the pelvic floor musculature, which may lead to improved urethral closure. It is also believed that through the process of reinnervation, pelvic floor stimulation may improve partially denervated urethral and pelvic floor muscles.
NON-IMPLANTABLE ELECTRICAL STIMULATION (NIES)
Depending on the etiology of incontinence (i.e., detrusor instability, stress incontinence), NIES utilizes variations in electrical pulse amplitude and frequency to mimic and stimulate different physiologic mechanisms of the voiding response. Methods of NIES have been varied in location (e.g., vaginal, rectal), stimulus frequency, intensity, or amplitude, pulse duration, pulse to rest ratio, treatments per day, number of treatment days per week, length of time for each treatment session, and overall time period for device use between clinical and home settings. Initial training occurs in a physician's office, followed by home treatment with a rented or purchased pelvic floor stimulator. There are currently several FDA-approved NIES devices for the treatment of urinary and/or fecal incontinence.
PEER-REVIEWED LITERATURE
Urinary Incontinence
In a prospective randomized controlled trial, Goode et al. (2003) evaluated the potential for NIES to improve the effectiveness of behavioral training for women with stress incontinence. Two hundred women with primary stress incontinence were scheduled to undergo either 8 weeks of behavioral training, behavioral training and home pelvic floor stimulation, or self-administered behavioral training alone using a self-help booklet. The primary outcome measurements included self-reported bladder diaries and changes in quality of life (QOL). Though individuals in all groups reported statistically significant improvements in incontinence, there was no statistically significant difference between the treatment groups. The authors concluded that treatment with NIES did not increase the effectiveness of a comprehensive behavioral program for women with stress incontinence.
In a single-blind, randomized comparative study, Wang et al. (2004) evaluated the safety and effectiveness of NIES (n=35) when compared to either pelvic floor muscle training (n=34) or biofeedback-assisted pelvic floor muscle training (n=34) in the management of overactive bladder (OAB). Biofeedback consisted of an intravaginal electromyographic probe, while an intravaginal electrode provided electrical stimulation. Individuals were followed during the 12-week treatment period. Outcome measurements included self-reported voiding diaries, QOL, and urodynamic measures. Both biofeedback and electrical stimulation groups reported an increased incidence of symptom resolution, though the authors did not describe how these outcomes were assessed. Improvement in overall QOL scores was significantly better in the NIES group when compared to the pelvic floor muscle training group. There were no statistically significant differences in voiding diary scores. The authors concluded that NIES had the greatest reduction rate of OAB. The study is limited in its heterogeneous design and lack of long-term follow-up.
In a randomized controlled trial, Castro et al. (2008) compared the effectiveness of NIES to pelvic floor exercises, vaginal cones, and no active treatment in women with urodynamic stress urinary incontinence. All of the active interventions consisted of 3 sessions per week under the supervision of a trained physical therapist. A total of 116 women were randomized and treated for 6 months, at which time they were assessed for reductions in stress urinary episodes and QOL. A statistically significant reduction in the number of stress urinary episodes and a significant improvement in QOL were found for individuals who used the active treatments when compared to no active treatment. However, no statistically significant difference was found between groups in urodynamic parameters. The authors concluded that active treatment was more effective than no active treatment in women with urinary stress incontinence. The study is limited in its loss to follow-up (14%) and heterogeneous treatment design.
In a Cochrane systematic review, Berghmans et al. (2013) evaluated the safety and effectiveness of NIES for the treatment of post-prostatectomy urinary incontinence in men. The authors identified 6 randomized controlled trials, noting that there was considerable variation in the interventions, study protocols, populations, and outcome measures. A total of 544 men were included, of whom 305 received some form of NIES, with 239 acting as a control or comparative treatment. In a pooled analysis of 4 randomized controlled trials comparing a combination of NIES and pelvic floor muscle exercises to pelvic floor muscle exercises alone, there was no statistically significant difference between groups at 3-month follow-up. The authors concluded that there was some short-term evidence of NIES enhancing the effect of pelvic floor muscle exercises, though not after 6 months. They also reported more adverse effects with electrical stimulation, including pain and discomfort. The study is limited in its heterogeneous design.
In a systematic review, Imamura et al. (2010) evaluated the clinical effectiveness of non-surgical treatments for women with stress urinary incontinence. Specific to NIES, the authors identified 8 randomized controlled trials comparing electrical stimulation to no active treatment, with a sham control being used in 6 of the studies. A pooled analysis of the studies did not find a statistically significant difference between groups in symptom relief. When stratified by studies which compared NIES to pelvic floor muscle training (n=5), there was no statistically significant difference between groups. The authors concluded that there was insufficient evidence to recommend NIES on a routine basis for treatment of stress urinary incontinence.
In a 2012 comparative effectiveness review, the Agency for Healthcare Research and Quality (AHRQ) identified 9 randomized controlled trials evaluating electrical intravaginal stimulation in women with urgency, stress, or mixed incontinence, with one study published after 2000. A pooled analysis of continence rate improvements comparing NIES to no active treatment yielded a relative risk of 2.01. AHRQ concluded that NIES was associated with increased continence rates and improvement in urinary incontinence. The review is limited in its heterogeneity as electrical stimulation was conducted under variable stimulation parameters, including length of treatment, depending on the type of urinary incontinence being treated.
Fecal Incontinence
In a randomized controlled trial, Norton et al. (2006) evaluated the effectiveness of NIES for the treatment of fecal incontinence in 90 adults. Study participants used a home electrical stimulation device for 8 weeks. Those allocated to active treatment had stimulation set at 35 Hz with a 0.5 second ramped pulse. The sham stimulator looked identical, but stimulation was set at 1 Hz. The primary outcome measurement was self-reported improvement. There was no statistically significant difference between groups in self-reported improvement. The study is limited in its high loss to follow-up (22%), short-term follow-up, and design.
In a Cochrane systematic review, Hosker et al. (2007) evaluated the effectiveness of NIES for the treatment of fecal incontinence in adults. Four eligible trials, representing 260 individuals, were identified. One trial was sham-controlled, 2 used NIES as an adjunct treatment, and 1 compared NIES to levatorplasty, a surgical procedure which combines the posterior liberation of the levator with the levator plication. The authors did not pool study findings due to the heterogeneous design of the included studies. Although all included studies reported general symptom improvement, it was noted that it was not clear whether symptom resolution was clearly due to NIES. The authors concluded that there was insufficient evidence to draw conclusions on the effectiveness of NIES for treating fecal incontinence.
In a systematic review, Vonthein et al. (2013) evaluated the effectiveness of biofeedback and/or NIES for the treatment of fecal incontinence. Thirteen studies evaluating biofeedback and/or NIES were included and reported symptom resolution and response rates using validated scales. A pooled analysis did not find a statistically significantly higher rate of symptom resolution with NIES when compared to controls. However, when comparing the combination of NIES and biofeedback with NIES alone, there was a significantly higher rate of symptom resolution with combination intervention. The authors concluded that individuals may benefit from combination biofeedback and NIES treatment when compared to biofeedback alone. The study is limited in its heterogeneous design. Additionally, the systematic review was primarily focused on biofeedback and does not allow conclusions to be drawn about NIES alone for the treatment of fecal incontinence.
MAGNETIC PELVIC FLOOR STIMULATION (MPFS)
MPFS or pulsed magnetic neuromodulation utilizes extracorporeal magnetic innervation (ExMI™) technology to deliver nerve impulses to the pelvic floor area to increase muscular contractions in an attempt to improve bladder control. The NeoControl® Pelvic Floor Therapy System is FDA-approved for the treatment of urinary incontinence in women. The system consists of a control unit and treatment chair. Pulsed magnetic fields generated by the chair's therapeutic head stimulate the perineal tissues, nerves, and muscles, reportedly increasing contractions and improving circulation. The treatment is typically performed twice a week, with each session lasting approximately 20 minutes. A complete course of treatment may take 8 weeks or more depending on the condition of the pelvic floor muscles when therapy is started.
PEER-REVIEWED LITERATURE
In a randomized controlled trial, Yokoyama et al. (2004) evaluated the safety and effectiveness of MPFS, utilizing a NeoControl® Pelvic Floor Therapy System, for the treatment of urinary incontinence when compared to functional electrical stimulation (FES). Thirty-six male individuals with urinary incontinence after retropubic radical prostatectomy were randomly assigned to three groups (12 each in FES, MPFS, and control groups). Outcome measurements included bladder diaries, 24-hour pad weight testing, and a QOL survey at 1, 2, and 4 weeks, and 2, 3, 4, 5, and 6 months, after catheter removal. At one month after catheter removal, pad weight was statistically significantly lower in the FES group than in the control group; at 2 months, pad weight was statistically significantly lower in the MPFS group; and at 3 months, there were no statistically significant differences in pad weight between the groups. QOL measures decreased after surgery, but gradually improved over time in all three groups. However, there were no statistically significant differences between the groups. There were no complications noted in any of the groups, as well. The authors concluded that both MPFS and FES were recommended for patients who seek quick improvement of postoperative urinary incontinence. The study is limited in its small sample size and indicates that at mid-term follow-up, there is no evidenced statistically significant difference between the control and MPFS groups.
In a double-blind randomized controlled trial, Gilling et al. (2009) evaluated the safety and effectiveness of MPFS for treating stress urinary incontinence (SUI) when compared to sham electromagnetic stimulation (SES). Seventy women with urodynamically confirmed SUI were randomized in a 1:1 ratio to receive MPFS or SES. Outcome measurements included a 20-minute pad-test, a 24-hour pad test, a 3-day bladder diary, and a QOL survey. Patients were evaluated 8 weeks after treatment, and the bladder diary, QOL survey, and pad-test were repeated at 6 months. At 8-week follow-up, there were statistically significant improvements from pre-treatment scores in the 20-min pad-test, the 24-hour pad-test, and the QOL survey. However, these improvements were not statistically significantly different when compared with the SES group. The authors did note that among patients who had a poor pelvic floor contraction at initial assessment (defined by circumvaginal muscle rating score and perineometry), there was a statistically significant reduction in the 20-minute pad-test leakage when compared with the SES group. The authors concluded that PMFS was no more effective than SES for the treatment of SUI. The study is limited in its post-hoc sub-group analysis with respect to conclusions about individuals with poor pelvic floor contraction.
In a randomized controlled trial, Wallis et al. (2012) evaluated the safety and effectiveness of MPFS for the treatment of women aged 60 years and older who have had urinary incontinence for 6 months or more. Patients were randomly assigned to the MPFS group (n=50) or the placebo group (n=51). Outcome measurements included a 24-hour pad test, an incontinence severity index, a 24-hour bladder diary, and a Bristol Female Lower Urinary Tract Symptoms questionnaire (BFLUTS-SF; measures the frequency and severity of symptoms). The authors found no statistically significant differences between the groups in any of the outcome measurements from baseline to 12-week follow-up. They concluded that any initial evidence of subjective improvement in the treatment group compared to the placebo group was not sustained with sensitivity analysis.
In an industry-sponsored, randomized sham-controlled study, Yamanishi et al. (2013) evaluated MPFS in women with urinary urgency. Individuals received either sham stimulation (n=50) or SMN-X (n=101), a non-FDA approved MPFS device manufactured in Japan, 2 times a week for 6 weeks. The primary outcome measurement was the self-reported change in the number of urinary incontinence episodes per week. The decrease in the weekly number of incontinence episodes was 13 in the MPFS group compared to 9 in the sham control group, representing a statistically significant difference (p = 0.038). Individuals in the MPFS group also had better results on secondary outcome measurements including number of urgency episodes per day, though the results were not statistically significant for the number of voids per day. The authors concluded that MPFS was effective for the treatment of urgency incontinence in female individuals with OAB. The study is limited in its lack of long-term follow-up.
SUMMARY
Various professional societies and expert groups have issued position statements regarding NIES and MPFS for the treatment of urinary and fecal incontinence. In 2006, the National Institute for Health and Clinical Excellence (NICE) issued a guideline on the management of urinary incontinence in women. NICE noted that perineometry or pelvic floor electromyography as biofeedback should not be used as a routine part of pelvic floor muscle training, but that electrical stimulation and/or biofeedback should be considered in individuals who cannot actively contract pelvic floor muscles to aid motivation. However, NICE noted that further research into optimal electrical stimulation parameters was required to inform clinical practice. In an updated 2013 guideline, NICE noted that electrical stimulation should not be routinely used in the treatment of women with OAB or in combination with pelvic floor muscle training.
In 2007, NICE issued a guideline on the management of fecal incontinence in adults. The guidelines noted that the evidence on electrical stimulation for the treatment of fecal incontinence was inconclusive. In 2012, the European Association of Urology (EAU) published clinical guidelines on the non-surgical management of urinary incontinence. The guidelines indicated that existing randomized controlled trials were of poor quality with short follow-up and inconclusive effects. The EAU determined that there was no consistent evidence regarding the effectiveness of NIES and MPFS for the cure or improvement of urinary incontinence and did not recommend treatment. In an updated 2014 guideline on urinary incontinence, the EAU determined that there was inconsistent evidence on whether NIES was effective in improving urinary incontinence compared to sham treatment or that it added benefit to pelvic floor muscle training. The EAU concluded that MPFS does not cure or improve urinary incontinence. In 2014, the American College of Physicians issued guidelines on the nonsurgical management of urinary incontinence and NIES and MPFS were not discussed.
The current state of evidence indicates that there is a paucity of peer-reviewed literature documenting the safety and effectiveness of pelvic floor stimulation for the treatment of urinary and fecal incontinence. There exist some randomized controlled trials which indicate that there may be no sustained statistically significant differences between pelvic floor stimulation and placebo for the treatment of incontinence. Additionally, there are several guidelines which suggest that the current available studies are inconsistent and of poor quality. There are few, if any, studies evaluating the safety and effectiveness of MPFS for the treatment of fecal incontinence. Therefore, questions remain regarding the safety and effectiveness of NIES and MPFS for the treatment of urinary and fecal incontinence.
