11th January 2014
Implantable device can reduce sleep apnea by 70 percent
Implantation of a sleep apnea device called Inspire Upper Airway Stimulation (UAS) therapy can lead to significant improvements for patients with obstructive sleep apnea (OSA), according to a study published in the New England Journal of Medicine. After one year, patients using the device had an average 70 percent reduction in sleep apnea severity, as well as significant reductions in daytime sleepiness.
Sleep apnea is a disorder characterised by pauses in breathing, or shallow and infrequent breathing, during sleep. Each of these pauses in breathing, called an apnea, can last from seconds to minutes, and may occur 30 times or more an hour. When normal breathing returns (sometimes accompanied by a loud snort or choking sound), the body moves out of deep sleep and into a lighter sleep. This results in poor overall quality of sleep and excessive tiredness during the daytime – increasing a person's risk for heart attack, stroke, high blood pressure and even death.
It is estimated that seven percent of Americans are affected by at least moderate sleep apnea. For those in middle age, this figure is higher, with as many as nine percent of women and 24 percent of men in this age group being affected, undiagnosed and untreated.
The costs of untreated sleep apnea reach further than just health issues. It is estimated that in the U.S. the average untreated patient's health care costs $1,336 more annually than an individual without sleep apnea. This may cause up to $3.4 billion/year in additional medical costs.
Treatments can include weight loss, upper airway surgeries, oral appliances, and continuous positive airway pressure (CPAP). However, while CPAP can be successful if used regularly, up to half of patients are unable to use it properly – largely due to discomfort with the mask and/or lack of desire to be tethered to a machine.
That's where a new device created at the University of Pittsburgh may help. Director of the UPMC Sleep Medicine Center, and lead author of the study, Dr Patrick Strollo, explains: "Inspire UAS therapy differs from other traditional sleep apnea devices and surgical procedures in that it targets muscle tone of the throat, rather than just the anatomy. Two thirds of patients using the device had successful control of their apneas, although even more reported improvement in snoring, daytime sleepiness and quality of life measures. Eighty-six percent of patients were still using the device every night at the one year mark, which compares very favourably to CPAP. The results of this trial show a huge potential for a new and effective treatment that can help millions of patients."
The device was fitted in three areas: a stimulation electrode was placed on the hypoglossal nerve, which provides innervation to the muscles of the tongue; a sensing lead was placed between rib muscles to detect breathing effort; and a neurostimulator was implanted in the upper right chest, just below the clavicle bone. Patients used a "controller" to turn on the device at night, so it was only used when the patient slept. The Inspire UAS therapy device was able to sense breathing patterns and to stimulate tongue muscles, thereby enlarging and stabilising the airway for improved breathing.
Kathy Gaberson, one of the study participants: "My short-term memory has improved significantly, and the surgery has made a huge difference in my quality of life. My apnea episodes went from 23 times an hour to just two."