Sacral nerve stimulation technology that is benefitting many overactive bladder (OAB) patients is gaining momentum for the treatment of fecal incontinence (FI). Molly Ford, M.D., colon and rectal surgeon at Vanderbilt University Medical Center, reports that referrals for this procedure are on the rise. “We are seeing 80 percent or more of our patients significantly helped by the device. I think they are going back to their primary care or GI doctors and spreading the word that it works,” Ford said.
FDA-approved for OAB since 1997, Medtronic’s Interstim™, a sacral nerve stimulator, won approval for fecal incontinence in 2011. Ford studied the technology in her fellowship and brought the procedure to Vanderbilt in 2014.
“It was slow to catch on at first, mostly because there are a lot of misconceptions about fecal incontinence.”
“It was slow to catch on at first, mostly because there are a lot of misconceptions about fecal incontinence. Many providers think there is nothing to do for FI beyond medical management, sphincter repair — which generally does not have sustained results — or colostomy,” Ford said.
Identifying Candidates for the Device
One or more incident a week in which there is loss of bowel control or even significant urgency that requires close proximity to a bathroom, can qualify someone as a candidate for a sacral nerve stimulator. Women are much more likely to have FI due to shorter anal canals and childbirth-related pelvic floor damage that catches up with them as muscle atrophies with age. While Ford treats some younger women, most of her patients are 50 and over.
By the time most patients come to Ford and her team, their incontinence has escalated far beyond occasional urgency or leakage, to a condition that is limiting their lifestyle and may be confining them at home.
First-line therapy for FI is medical management, which includes pelvic floor physical therapy and strengthening exercises, dietary fiber and Imodium® (assuming no constipation issues). To be a candidate for the sacral nerve stimulator, patients must first “fail” this medical management.
Patients who have daily FI episodes have the option to undergo an office-based test wherein a thin wire is inserted through the lower back into the sacral complex (S3 region), with a portable device worn on a belt delivering stimulation. If improvement is noted after five days, the physician removes the test wire and implants the formal device, Ford explained.
Another option is the two-week test, where the surgeon inserts a tined electrode into the sacral complex and out again to a temporary controller worn on a belt. If the patient experiences a 50 percent or greater improvement over that period, the patient may have the temporary external controller replaced by the formal implantable neurostimulator. Positioning of this device is in on the upper buttock.
Studies suggest stimulating the sacral complex helps normalize sensory signal processing in the spinal cord. The result is a nerve-based functional change in muscle control. Since the stimulation works better on some patients than others, office-based tests are necessary to determine who will benefit.
FI and OAB devices are implanted in the same place, yet with OAB devices, stimulation is patient-controlled and there is a bladder “training” benefit that continues for some time if the stimulation is turned off. With the FI application, stimulation is continual, but the patient has some control over the program and the settings. Removing the stimulation generally returns the patient to a state of incontinence.
Quality of Life Improvements
While Ford says a urologist may perform 20 to 30 OAB implants a year, the rate of implants for FI is lower, but escalating as word spreads about the success rates. This year her team is on track to perform more than double what they did last year.
“It’s probably the procedure that makes patients happier than any other procedure I do.”
Success is defined as a 50 percent reduction in episodes, but many of Ford’s patients have better results and some are free of FI episodes altogether. “It’s probably the procedure that makes patients happier than any other procedure I do,” she said. “I have had more people go from truly being a shut-in to functioning in society. I have patients who say, ‘I just want to go to church and have lunch with my friends.’ They come back post-op and they’re back to doing these things and more.”