By Eva Briggs, MD
Recently a friend asked me about the Inspire device to treat sleep apnea. I wasn’t familiar so I looked it up. Here is what I learned.
Sleep apnea refers to stopped breathing occurring during sleep. There are several types: obstructive, central and mixed.
• Obstructive sleep apnea occurs when changes in the shape of the mouth and throat during sleep block air passage. It becomes more common with age. Examples include the tongue falling back against the soft palate or large tonsils. Symptoms include snoring or gasping during sleep, feeling drowsy during the day, trouble concentrating, dry mouth and headaches. But even children, such as those with enlarged tonsils or adenoids, can have OSA.
• Central sleep apnea occurs when the brain and nervous system fail to signal the body to breathe. Symptoms include daytime sleepiness, awakening feeling panicked or short of breath and insomnia. Causes include sedating drugs, sleeping at high altitudes and congestive heart failure. Some cases are idiopathic meaning there is no known underlying cause.
• Mixed sleep apnea combines both OSA and central sleep apnea.
The Inspire device treats OSA. Other treatments for OSA include CPAP (continuous positive airway pressure), surgical interventions to change the shape of the upper airway and oral appliances. The Inspire can treat patients that have tried and failed less invasive treatments.
The Inspire is designed to stimulate the genioglossus muscle, a muscle whose contraction moves the tongue forward thus opening
the airway.
There are three components to the device. First is a small impulse generator, which is implanted under the collar bone. Second is a breathing sensor tunneled from the impulse generator to the chest wall muscles. This detects when the person is inhaling, telling the impulse generator to send a signal to the tongue to move forward. The third piece is a lead that tunnels from the impulse generator to a nerve stimulator lead placed on a branch of the hypoglossal nerve at the base of the tongue.
Candidates for this procedure must meet strict criteria. First is age, it’s used in adults older than 21. Second is moderate to severe OSA. The patient must have a body mass index less than 33. Patients must have first tried CPAP and have had trouble tolerating it. Candidates for the procedure must not have significant additional medical problems such as neuromuscular disease, severe heart disease, severe lung disease or significant psychiatric illness. There should be no pronounced upper airway anatomic abnormalities. The patients must also undergo endoscopy during drug-induced sleep that demonstrates airway changes that could be helped by the device.
The procedure for eligible patients is as follows. It is done as an outpatient. There are two incisions. One is under the collarbone to place the battery-powered device. A second incision under the chin is used to place the lead wiring connecting to the nerve at the base of the tongue. The surgery takes about two hours and is performed with general anesthesia. The patient can go home the same day.
After one month, when sufficient healing has occurred, the patient returns for follow up at which time the device is activated. The patient can then use a remote to activate the device in the evening and turn it off in the morning. The Inspire will require periodic adjustment. The battery is expected to last 10 years before requiring replacement.
As with any surgery, there are risks including bleeding, infection, tongue weakness, tongue numbness, facial weakness, voice change, lung collapse (pneumothorax), limitations of the ability to undergo MRI and tooth movement.
So, as you can see, it is not simple to determine who is a good candidate for the Inspire device. And it is a somewhat involved procedure. So, interested people would need to consult with an appropriately trained specialist.
Eva Briggs is a retired medical doctor who practiced in Central New York for several decades. She lives in Marcellus.