Sacral Nerve Stimulation for Fecal Incontinence
By Marja Sprock, MD // May 8, 2012
Fecal incontinence, the chronic involuntary loss of stool is a humiliating, debilitating and life altering condition that is often underreported and stigmatized. Greater than 50 percent of patients with severe fecal incontinence report a significant impact on quality of life, including impact on their ability to work or engage in social activities.
According to the National Institutes of Health, more than 5.5 million Americans have fecal incontinence. The prevalence of fecal incontinence is about 2% in the entire population being more common in adults, predominately women, but it is not a normal part of aging. It is reported that fecal incontinence is present in 11% of men and 26% of women over the age of 50.
There are different types of fecal incontinence:
- Passive fecal incontinence: individual is not aware of the passing of feces
- Urge fecal incontinence: individual senses an urgent need to defecate and cannot or barely make it to the toilet
The reasons for developing fecal incontinence vary, and include damage to the nerves or muscles in the rectum (from trauma such as childbirth), diabetes, post-operative complications from ano-rectal surgery, and neurogenic or spinal problems. Because of the influence of vaginal deliveries on the occurrence of fecal incontinence the prevalence of fecal incontinence is twice as high in women.
The first line of treatment includes change of diet, muscle biofeedback pelvic floor muscle training and anti -diarrhea/constipating measures. Biofeedback has been successful in retraining pelvic floor muscles for better-coordinated stool storage and controlled defecation.
Surgical options such as post-anal repair or anterior direct or overlapping sphincter repairs have mediocre results for curing fecal incontinence, with long-term success rates of 35-50% or less.
For patients whose fecal incontinence has been unsuccessful on traditional therapy or who have experienced intolerable side effects from medications, sacral neuromodulation with InterStim Therapy may provide relief from fecal incontinence.
Several studies have been performed with implantation of an Interstim® device. The InterStim® device stimulates the sacral nerve, usually at the S3 level, however sacral foramen 2 and 4 have also been used. Initially used for urinary incontinence, it was found to have an excellent result for fecal incontinence also.
InterStim has been approved for treating both urinary and fecal incontinence in Europe since 1994, in the USA for urinary incontinence since 1997 and recently approved for fecal incontinence in 2011.
Results of InterStim implantation have been very encouraging. One of the studies, which was instrumental in FDA approval showed perfect continence in 40% of the study subjects, with 30% achieving 75% or greater improvement. Another very important finding is that the achieved continence continues or improves slightly over time. In other words if it affects a good initial outcome the chances are high that continence will be sustained.
As with any medical treatment, some people may experience some of the following side effects with sacral neuromodulation:
- Pain where the device is implanted
- The electrodes change position in the body
- Infection or skin irritation
- Technical problems
- Adverse changes in bowel or bladder function
- Numbness at the neurostimulator site
- Undesirable stimulation or sensations.
The number of people with these side effects has been very low and, in almost all cases they were solved.
It is important that InterStim Therapy be tested to ensure efficacy before a commitment is made to implant the permanent device. The trial assessment involves placing a thin wire under the skin in the lower back. The wire is connected to a small external test stimulator, which is worn on a belt. The test stimulator sends mild electrical pulses through the thin wire to the sacral nerves. For fecal incontinence we usually use a test lead that stays in for 10-14 days, during which the patient may continue daily activities, with caution. If the screening trial provides a good response, it is highly predictive of a good response with the full implant.
The Interstim® is a minimally invasive, low risk intervention requiring a short operation (about one hour) in an operating room. The insertion is comparable to a heart pacemaker implantation and is done under local anesthesia. A small incision is made in the upper buttock where the neurostimulator device is inserted under the skin. A small incision is also made in the lower back where a long-term electrode is inserted next to the sacral nerves. The neurostimulator sends the electrical pulses through this thin wire to the sacral nerves.
After the Procedure
After the surgery, the neurostimulator is programmed to give the same stimulation as during the trial assessment, and the patient is shown how to use the patient programmer for self-adjustment of the device the settings.
Activities may need to be restricted for a short while after the surgery, and at first, the patient may also feel the sensation of the neurostimulator and the electrical pulses, but only for a short time.
The cost of the implant is substantial and is usually covered by insurance.
InterStim success stories are numerous, but most people may be reluctant to openly talk about fecal incontinence. A successful Interstim® insertion may make all the difference for you or your friend with fecal incontinence.
Come on in to Central Florida UroGynecology where we will talk about, diagnose and treat fecal incontinence, and where the experience with the Interstim® is extensive. We are in Rockledge or look us up on www.CFUroGyn.com