Inspire Hypoglossal Nerve Stimulator Surgery for Sleep Apnea Treatment

If you have obstructive sleep apnea, you may be interested in exploring surgical treatment options. One such option is the hypoglossal nerve stimulator called Inspire. What is Inspire? Who should consider using it and what are the side effects? Learn about the Inspire upper airway stimulator and whether it might be the right therapy for you.

The Inspire stimulator is a surgically implanted device that activates the hypoglossal nerve to tighten the muscles of the tongue and upper airway during sleep, improving airflow and reducing sleep apnea. It is approved for use by those with:

• Moderate to severe obstructive sleep apnea (apnea-hypopnea index or AHI >15)
• Non-compliance with CPAP therapy after a trial
• Body-mass index (BMI) less than 32, excluding those with morbid obesity

There are also a few relative contraindications to the use of Inspire therapy. If the obstruction contributing to sleep apnea is occurring within the nose, due to allergies or a deviated nasal septum, it will be ineffective. Similarly, certain skeletal anatomy (such as a small or recessed lower jaw) may be a reason to not pursue the treatment. If tonsils are enlarged, surgery targeting these tissues may be more appropriate. Certain neuromuscular conditions that affect the ability to swallow or contribute to slurred speech may also be a contraindication. If frequent MRIs are needed for other medical conditions, the device is not safe for use with these studies. The treatment is not approved for use in children.

Most people who undergo Inspire surgery have moderate to severe sleep apnea and have failed CPAP therapy, despite their best efforts. They continue to have symptoms, and may be desperate for an effective solution. Surgery may be appealing as a more permanent fix to a problem that may not otherwise go away.

It is important to have a comprehensive understanding of the role of this treatment in your condition. The first choice for the treatment of obstructive sleep apnea is the use of continuous positive airway pressure (CPAP). Success with this treatment requires proper mask fitting and optimal device settings. In some cases, alternatives such as weight loss, bilevel therapy, the use of an oral appliance, or positional therapy can be pursued. In some cases, nothing seems to work.

Once you have exhausted treatment options with your board-certified sleep physician, it may be necessary to consider the role of the Inspire hypoglossal nerve stimulator. Consider some of these questions to ask the surgeon:

• Am I good candidate for the surgery in your experience?
• If I couldn't do this surgery, what would you recommend as treatment instead?
• How often have you done this procedure?
• What is your success rate in resolving sleep apnea (AHI <5)?
• How many patients have complications such as bleeding, infection, or device removal?
• How will I know if the therapy works well for me?
• Do you have support to work through the insurance approval process?
• Will I have testing after the device is placed to determine settings and response to therapy?
• Who will I follow up with once the surgery is complete?

There may be additional considerations based on your specific circumstances.

After a consultation with the sleep surgeon, you will likely have a procedure called a drug-induced sleep endoscopy to assess your anatomy. In a controlled environment, a medication will be administered that causes unconsciousness and muscle relaxation. This helps to determine whether your airway collapses completely from all sides. If it does, surgery may not be effective and the procedure would not be performed. If this test demonstrates appropriate anatomy, then surgery will be arranged.

Inspire must be placed during surgery with general anesthesia in an operating room. Preceding the placement, another procedure called drug-induced sleep endoscopy may be performed to assess your airway anatomy and whether the device is likely to be effective. Some patients, called non-responders, do not benefit from the treatment. This is more likely if the airway seems to completely collapse from all sides during the endoscopy procedure.

Once you are determined to be a candidate, a specially trained ear, nose, and throat (ENT) specialist performs the surgery as an outpatient procedure. The stimulation wire is placed leading to the hypoglossal nerve and wraps one of its distal branches. A second sensing lead is placed along the rib cage to detect breathing so the tongue muscle and airway can be stimulated at the proper time as breath is drawn in. Finally, the stimulator itself is placed within the right upper chest wall and connected to the sensors. The entire procedure takes about 2 hours.

After the surgery, patients usually go home if there have not been any complications. Most do not require the use of narcotic pain medications. It is recommended that strenuous activity be avoided for 2-3 weeks following the surgery. A regular diet can be consumed without any necessary modifications.

Inspire airway stimulation is a relatively effective treatment for moderate to severe obstructive sleep apnea when CPAP is not tolerated.

Studies have shown that at 12 months it reduces the AHI from 29.3 to 9.0 events per hour, on average, representing a 68% reduction. It should be noted that the residual AHI still represents mild sleep apnea. This may improve as the therapy is optimized and appropriate candidates are identified.

Excessive daytime sleepiness seems to improve as well. Scores on the Epworth sleepiness scale improved from 11 to 6 with treatment, suggesting a reduction in daytime sleepiness.

When the device is turned off, sleep apnea mostly returns.

There are few complications to the placement of the Inspire device. About 25% of patients complained of relatively modest pain. About 1/3 of patients complained of tongue discomfort or abrasion, but this seemed to resolve in time.

About 1% developed skin infection or irritation (cellulitis) from the surgery and another 1% had to have another surgery to correct the device placement.

The treatment is generally well-tolerated once healing from surgery has occurred. Some people find the sensation within the tongue is uncomfortable when the device is activated during sleep. This rarely requires intervention. Additional side effects include:

• Excessive bleeding
• Damage to the nerve
• Infection
• Allergic reaction or rejection of the implanted materials
• Persistent pain at implant site
• Discomfort from stimulation
• Tongue soreness or weakness
• Tongue movement restrictions
• Difficulty swallowing or speaking
• Scarring or fibrosis around the implant
• Dry mouth
• Insomnia
• Other acute symptoms (i.e., headaches, coughing, choking)

If these symptoms persist, it may be important to discuss the severity and impacts with the surgeon.

After the surgery is completed, patients return to see the surgeon for a post-operative check at 7-10 days. The device is turned on at 1 month. It is recommended to have an in-center sleep study at 2 months to assess its effectiveness and adjust the settings.

Once placed, the Inspire stimulator can be activated before going to sleep. There is usually a delay of 30 minutes before the stimulation begins. If you wake at night, the device can be paused. It is often set to turn off after 8 hours.

How much does the treatment cost? The Inspire device presently costs about $30,000 to $40,000 to place, including the expenses associated with surgery, and the replacement of the battery can cost another $17,000. These costs may be covered by insurance.

If you are interested in learning more about the Inspire upper airway stimulator as a treatment option for you, contact a provider near you to discuss this option. Sleep specialists can also provide information about alternative treatments, including the optimized use of CPAP, oral appliances, and other therapies.