By AMANDA PEDERSEN
Medical Device Daily Senior Staff Writer
While most people think of pacemakers as the small electrical devices implanted in a person's chest or abdomen to help control abnormal heart rhythms, Medtronic (Minneapolis) is offering a similar device one that is implanted in a patient's lower backside to help control incontinence.
The company says its InterStim system delivers sacral neuromodulation therapy that helps control the symptoms of overactive bladder, non-obstructive urinary retention and chronic fecal incontinence through modulation of the nerves that are believed to regulate activities of the bladder, bowel, urinary, and anal sphincters, and pelvic floor muscles. Mild electrical pulses are delivered to the sacral nerves through the implantable InterStim system, which includes a thin wire lead and a neurostimulator, which is about the size of a stopwatch. The stimulation parameters are controlled by external, handheld clinician and patient programmers.
First offered for bladder and urinary incontincence in 1997, the FDA approved the use of the device for bowel control a little more than a year ago (Medical Device Daily, April 4, 2011). Last month, as part of Medtronic's fourth quarter earnings report, the company noted that sales of InterStim for both urinary and bowel indications drove growth in the company's neuromodulation revenue, which was up 8% for the quarter at $463 million.
A study funded by the National Institutes of Health suggests that more than 18 million Americans have fecal incontinence. It is more common in adults, predominately women, but it is not a normal part of aging. Fecal incontinence can be caused by a variety of factors, including damage to the nerves or muscles in the rectum from trauma such as childbirth, or other pelvic health disorders.
According to the company, the InterStim Therapy is the only bowel control treatment option that allows patients and physicians to determine probable success of the therapy through a test stimulation procedure prior to committing to long-term therapy.
"Bowel control problems can have a significant, detrimental effect on a person's emotional well-being and quality of life. Standard treatments often fail due to both the inherent challenges of the condition and the fact that few effective treatment options are available," said Steven Wexner, MD, chief academic officer at Cleveland Clinic Florida (Weston), professor and chair of the Department of Colorectal Surgery, and president-elect of the American Society of Colon and Rectal Surgeons (Arlington Heights, Illinois). "I applaud the application of promising technology to advance treatment options for many who suffer with chronic fecal incontinence."
Wexner was the lead principal investigator during the Medtronic-sponsored pivotal trial that served as the basis for the application to the FDA. After completion of the study, he began working as a paid consultant assisting Medtronic in the development of educational materials relating to this therapy, "because I think it's a good technology," he told Medical Device Daily.
The company notes that clinical research has demonstrated the InterStim's effectiveness at reducing episodes of urinary incontinence, urgency and frequency, non-obstructive urinary retention, and fecal incontinence.
The most common adverse events experienced during clinical studies of patients with sacral neuromodulation included pain at implant sites, new pain, lead migration, infection, technical or device problems, adverse change in bowel or voiding function, and undesirable stimulation or sensations. Any of these may require additional surgery or cause return of symptoms, the company noted.
The InterStim system is also FDA approved for MRI head scans under specific conditions, Medtronic noted. Equally important if not more so, the therapy is reversible, it can be turned off or surgically removed at any time.
Interestingly, Wexner told MDD, the device tends to work in more of a neurological way than physical. "It seems to be more like a perception difference or a better early warning system, not really motor. It's not really making the anal sphincter work better . . . it gives the patient the improvement in the urge to go."
That is one key difference between the InterStim system and other therapies available for patients suffering incontincence, particularly for the bowel indication. "All of the other therapies aim to create a barrier of some sort by either bulking the sphincter or replacing the sphincter," he said.
Wexner said he has experience with other treatment methods for fecal incontinence and that this one, compared to the others, yields better results, a lower complication rate, and is easy to do. Perhaps even more important, patients are generally open to trying the system, he said. "They have three out of four chances of getting better and people tend to go for that," Wexner said. "These are patients with severe incontinence . . . they're pretty open to suggestions" of things that might help them gain control over their symptoms.
Still, he added, this procedure is not for everyone. "We don't know who is the optimal candidate, but we're working on that."
Also, as with most any procedure, experience counts. "Patients should go to somebody with experience and the results are going to be dependant upon experience," Wexner said.
Earlier this year another company, Uroplasty (also Minneapolis), reported the first enrollment of patients in its CONFIDeNT study using the company's Urgent PC Neuromodulation System, a neuromodulation system deigned to deliver percutaneous tibial nerve stimulation (PTNS) for patients with overactive bladder and associated symptoms of urgency, frequency and urge (MDD, Feb. 17, 2012). The company also makes Macroplastique implants, an injectable urethral bulking agent for the treatment of adult female stress urinary incontinence primarily due to intrinsic sphincter deficiency.
Another Minneapolis-based company, Medspira, also makes a device for patients with constipation or fecal incontinence, which was just cleared by the FDA late last month (MDD, May 24, 2012). Anorectal manometry testing evaluates pelvic floor function in patients with constipation or fecal incontinence. Mespira says its mcompass was designed to make testing highly accurate, easy to perform and practical for a broad range of medical specialists. The mcompass comprises three components a disposable catheter, mobile tablet PC and wireless portable manometer.
Another competitor in the incontinence device space is Precision Medical Devices (PMD; Fort Lauderdale, Florida), which makes the Flow Control Device (FCD) for severe urinary incontinence. That device is a bionic implanted urethral valve that is remotely-controlled and telemetry adjustable. The FCD is designed to constrict the urethra to arrest the flow of urine.
Published June 19, 2012