Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea: A Comprehensive Guide

Introduction and Terminology

Obstructive Sleep Apnea (OSA) is a common sleep disorder characterized by repetitive episodes of partial or complete blockage of the upper airway during sleep. One innovative treatment option gaining momentum in the United States is Hypoglossal Nerve Stimulation (HNS). In essence, HNS is a surgically implanted device that modulates the activity of the hypoglossal nerve, which controls the movements of your tongue. When activated, the device stimulates the nerve, causing the tongue to protrude and hence prevent blockage of the airway during sleep. This procedure is generally reserved for patients who are unable to achieve satisfactory results with other non-invasive treatment options such as continuous positive airway pressure (CPAP).

Indications for Hypoglossal Nerve Stimulation

Determining whether HNS is the appropriate treatment for you involves a comprehensive evaluation by your healthcare provider. Key indications for this procedure include:

• Moderate to severe Obstructive Sleep Apnea (Apnea-Hypopnea Index, AHI, of 15 or higher).
• Inability to tolerate or benefit from CPAP therapy.
• Body mass index (BMI) less than 35 kg/m².
• Positional sleep apnea, where the condition worsens when you’re lying on your back.
• A lack of complete concentric collapse at the level of the soft palate during drug-induced sleep endoscopy (DISE).

It’s important to note that your provider will also consider your overall health status, the anatomy of your upper airway, and your personal preferences when discussing this treatment option. Furthermore, certain contraindications such as active infection or neurological disorders that may impair tongue movement can make you ineligible for HNS.

Pre-Op Preparation

Once your provider has recommended HNS and you’ve agreed to proceed, you will be given detailed preoperative instructions. General guidance includes:

• Fasting: Avoid eating or drinking for a certain period before your surgery, typically after midnight on the day of the procedure.
• Medications: Some medications may need to be stopped or adjusted. This includes blood thinners, certain supplements, and medications that may interfere with anesthesia.
• Pre-op labs and imaging: These tests provide essential information to your healthcare team and may be required to assess your fitness for surgery.
• Pre-clearance authorization: This is an approval process with your insurance company to ensure the procedure will be covered.
• Transportation: As you will be under anesthesia, arrange for someone to drive you home after the procedure.
• Work or school notes: Ensure you have obtained the necessary documentation for time off to recover.

Always consult your healthcare provider for precise instructions. Our telemedicine primary care practice can assist with pre-operative clearances and ordering of pre-op labs and imaging. Please remember that individual circumstances may warrant different approaches, so it’s essential to discuss this with your provider.

Procedure Technique for Hypoglossal Nerve Stimulation

Understanding the step-by-step process of the Hypoglossal Nerve Stimulation (HNS) procedure can help reduce anxiety and promote your active participation in your treatment. This complex medical procedure is presented here in an easily understandable format. Here’s what to expect.

Step 1: Anesthesia

The procedure starts with the administration of general anesthesia. This means you will be asleep and will not feel any pain during the procedure. An anesthesiologist will monitor your vital signs throughout the surgery.

Step 2: Making the Incisions

Three small incisions are made: one under the chin, one on the chest, and one on the side of the chest. These incisions provide access for the implantation of the device and its connecting leads.

Step 3: Positioning the Stimulation Lead

The stimulation lead is a small wire that is inserted via the incision under the chin. It is positioned around the hypoglossal nerve, which controls the movements of the tongue. This lead carries electrical signals from the device to the nerve.

Step 4: Implanting the Generator

The pulse generator, which is about the size of a pacemaker, is then implanted through the incision on the upper side of the chest. This generator produces the electrical signals needed to stimulate the hypoglossal nerve.

Step 5: Positioning the Sensing Lead

The sensing lead, another thin wire, is inserted via the chest incision. This lead detects your breathing patterns and sends this information to the pulse generator.

Step 6: Connecting the Leads to the Generator

Once both leads and the generator are in place, the leads are connected to the generator. The generator now has the information it needs to properly stimulate the hypoglossal nerve in response to your breathing patterns.

Step 7: Testing the Device
Before the incisions are closed, the device is tested to make sure it is working correctly and stimulating the nerve in the right way. Adjustments are made if necessary.

Step 8: Closing the Incisions
Finally, the incisions are closed using sutures, and dressings are applied. You will then be slowly awakened from the anesthesia.

Step 9: Recovery Room
After the procedure, you will be taken to a recovery room where your vital signs will continue to be monitored as you wake up from the anesthesia. You can expect to spend one night in the hospital for observation.

Please remember, this is a simplified explanation of the procedure, and the exact steps may vary based on your specific condition and your surgeon’s techniques. You should have an in-depth discussion with your surgeon about what the procedure will entail for you specifically.

Duration of Hypoglossal Nerve Stimulation

The Hypoglossal Nerve Stimulation (HNS) procedure typically takes about three hours. This timeframe includes preparation, the surgical procedure, and immediate recovery. Remember, this duration can vary depending on individual circumstances.

Post-Op Recovery from Hypoglossal Nerve Stimulation

Following the HNS procedure, you can expect a hospital stay of approximately one to two days. The exact duration can vary depending on your individual recovery speed. Initially, you will have follow-up appointments with your doctor one week after surgery, then at one, three, and six months, and annually thereafter.

Rehabilitation or physical therapy is typically not required after HNS. However, some lifestyle changes may be recommended, such as maintaining a healthy weight and adopting good sleep habits.

The time needed off work can vary, but most people can return to normal activities within one to two weeks after surgery. Full recovery from the procedure and resumption of all activities, including heavy lifting or strenuous exercise, usually occurs within four to six weeks. Our practice is committed to your recovery and can provide work or school notes, with same-day appointments available until 9pm on weekdays and 5pm on weekends.

Effectiveness of Hypoglossal Nerve Stimulation

Hypoglossal Nerve Stimulation (HNS) has demonstrated effectiveness in treating Obstructive Sleep Apnea (OSA). Studies have shown significant reductions in apnea-hypopnea index (AHI), an improvement in oxygen saturation levels, and enhanced quality of life for patients with moderate to severe OSA who cannot use or get consistent benefit from Continuous Positive Airway Pressure (CPAP).

The effectiveness of HNS is generally improved in patients with a lower body mass index (BMI), those with positional sleep apnea, and those who exhibit less complete concentric collapse at the level of the soft palate.

Certain factors, however, can lower the effectiveness of HNS. These include a high BMI, complete concentric collapse at the level of the soft palate, and certain neurological conditions that may impact tongue movement.

It’s crucial to discuss with your healthcare provider whether HNS is the right treatment option for you. Keep in mind that while the treatment has proven effective in many cases, individual results can vary, and it’s important to have realistic expectations about the outcomes.

Adverse Events with Hypoglossal Nerve Stimulation

As with any surgical procedure, Hypoglossal Nerve Stimulation (HNS) carries certain risks. These may include infection (5%), tongue weakness or numbness (8%), and difficulty swallowing (7%).

An infection may occur due to bacterial contamination during surgery. This is typically treated with antibiotics and, in rare cases, may require additional surgery.

Tongue weakness or numbness may occur as the nerve that controls the tongue is manipulated during the procedure. This is usually temporary and resolves over time.

Difficulty swallowing can occur due to changes in the nerve function that controls swallowing. This is typically a temporary condition that resolves over time.

The mortality rate associated with HNS is extremely low (below 0.1%), making it a relatively safe procedure for the treatment of Obstructive Sleep Apnea (OSA).

Alternatives to Hypoglossal Nerve Stimulation

While HNS is an effective treatment for OSA, it’s not the only option. Continuous Positive Airway Pressure (CPAP) therapy remains the first-line treatment for OSA. Oral appliances designed to keep the airway open can also be effective for some patients.

Surgical alternatives, such as Uvulopalatopharyngoplasty (UPPP), maxillomandibular advancement (MMA), and genioglossus advancement (GA), are also available. Lifestyle modifications, including weight loss, smoking cessation, and alcohol reduction, can also improve OSA symptoms.

Always discuss these alternatives with your healthcare provider to determine the best treatment plan for you.

Experimental or Emerging Technologies

Emerging technologies in the treatment of OSA include positional therapy devices, oral pressure therapy, and nerve stimulation systems targeting different areas than HNS. For example, Expiratory Positive Airway Pressure (EPAP) devices are small, non-prescription, single-use devices that fit over the nostrils and use the person’s own breathing to create positive airway pressure.

These experimental options represent a new generation of treatments that aim to be more patient-friendly and potentially more effective, but further research is needed to fully understand their benefits and risks.

Conclusion

Hypoglossal Nerve Stimulation (HNS) is a promising, effective treatment option for Obstructive Sleep Apnea (OSA). While it carries certain risks, the overall safety profile is favorable, and the procedure can significantly improve quality of life for patients who have not found relief from other treatments. Emerging technologies continue to evolve and may offer additional options for patients in the future.

Brief Legal Disclaimer: This article is for informational purposes only and not intended as medical advice. Always consult a healthcare professional for diagnosis and treatment. Reliance on the information provided here is at your own risk.