Inspire therapy is an innovative treatment for Obstructive Sleep Apnea (OSA) involving an implanted device that stimulates the hypoglossal nerve. This nerve controls the muscles that keep the upper airway open during sleep. Inspire offers an alternative for individuals who cannot tolerate or benefit from Continuous Positive Airway Pressure (CPAP) machines. The treatment is a highly specific surgical option requiring strict adherence to candidacy guidelines. These guidelines ensure patient safety and identify individuals most likely to respond successfully to nerve stimulation.
Specific Sleep Apnea Metrics
Individuals whose obstructive sleep apnea falls outside a specific severity range are generally not considered good candidates for hypoglossal nerve stimulation. The therapy is typically indicated for patients with moderate to severe OSA, defined by an Apnea-Hypopnea Index (AHI) that falls between 15 and 100 events per hour of sleep. Patients with mild OSA (AHI below 15) are usually excluded because less invasive treatments are often sufficient.
Conversely, patients whose AHI exceeds 100 events per hour may have respiratory compromise too severe for the device to effectively manage. While nerve stimulation maintains muscle tone and prevents collapse, it may not be powerful enough to overcome complete airway closure in the most severe cases. Therefore, the device operates best within the moderate-to-severe window (AHI 15-100).
Another absolute exclusion metric relates to the type of breathing event recorded during a sleep study. Inspire therapy is specifically designed to treat obstructive sleep apnea, caused by a physical blockage of the airway. Patients with a significant component of central sleep apnea (CSA) are not candidates, as CSA is a neurological condition where the brain fails to signal the muscles to breathe.
If central or mixed apneas—a combination of obstructive and central events—make up more than 25% of a patient’s total AHI score, they are typically disqualified. Since the device acts only on the muscles of the upper airway, it cannot correct the underlying signal failure in the brain that characterizes central sleep apnea. A detailed sleep study differentiating between event types is a mandatory step in the screening process.
A patient must also demonstrate a clear history of failure or intolerance to CPAP therapy to be considered for the implant. This criterion is not a metric of the disease itself but a mandatory prerequisite for surgical intervention. Disqualification occurs if the patient has not made a documented, consistent effort to use CPAP or if their sleep apnea can still be adequately treated by CPAP.
Anatomical and Physiological Limitations
The patient’s physical structure and pattern of airway collapse are common reasons for disqualification. A high Body Mass Index (BMI) is a frequent exclusion criterion, as excessive weight increases fat tissue surrounding the upper airway, hindering effective stimulation. While clinical data supports use up to BMI 40, many insurance policies and clinical practices still maintain a cutoff of BMI 35 or 32 for coverage and optimal outcomes.
The most absolute anatomical exclusion is the presence of complete concentric collapse (CCC) at the soft palate level, which is determined by a procedure called Drug-Induced Sleep Endoscopy (DISE). DISE involves briefly anesthetizing the patient to simulate sleep and then inserting a flexible camera to observe the airway collapse pattern. Complete concentric collapse means the soft palate and surrounding tissues collapse inward equally from all sides, creating a total, circular blockage.
The hypoglossal nerve stimulator works primarily by stimulating the genioglossus muscle, which causes the tongue to protrude forward, thereby opening the airway from the front. This mechanism is effective against obstructions caused by the tongue base or those with an anterior-posterior (front-to-back) or lateral (side-to-side) collapse. However, the device cannot effectively counteract the circumferential pressure of a complete concentric collapse, making it a clear contraindication for the therapy.
Other structural abnormalities in the upper airway can also lead to disqualification. Patients with severely enlarged tonsils (Mallampati 3 or 4) or significant craniofacial abnormalities are often poor candidates. These large obstructions may physically block the airway in a way that maximum nerve stimulation cannot overcome, leading to treatment failure.
General Health and Operational Constraints
Beyond the specific metrics of sleep apnea and anatomy, a patient’s overall health and ability to comply with the treatment regimen can disqualify them from receiving the implant. The therapy is generally restricted to adult patients, with standard protocols requiring individuals to be 18 years of age or older, although some specific indications target patients 22 years and older. The only exception is for a specific population of adolescents with Down Syndrome, for whom the device has been approved under specialized guidelines.
The presence of other implanted medical devices can conflict with the neurostimulation system. Devices such as pacemakers, implantable cardioverter-defibrillators (ICDs), or other nerve stimulators may interfere with the Inspire device’s electrical function. Patients with older models of the Inspire device may also face restrictions on undergoing Magnetic Resonance Imaging (MRI) scans, a limitation considered before implantation, although newer models are often conditionally safe.
Certain health conditions can make the procedure unsafe or render the device ineffective. Patients with uncontrolled high blood pressure, severe bleeding disorders, or other systemic issues that make general anesthesia or surgery high-risk are typically excluded. Any condition that has compromised the neurological control of the upper airway, such as prior neck surgery that damaged the hypoglossal nerve, will also disqualify a potential candidate.
Finally, the patient must demonstrate the cognitive and physical capacity to operate the system’s remote control consistently every night. The device requires the user to turn it on before falling asleep and turn it off upon waking. Patients with significant neurological or psychiatric conditions, such as severe dementia, who cannot reliably perform these daily tasks or attend necessary follow-up titration sessions, are not considered good candidates.