Care at NUH

Hypoglossal Nerve Stimulation


Hypoglossal nerve stimulation (HGNS) is a treatment for patients with obstructive sleep apnoea (OSA)by facilitating improved breathing during sleep. This treatment involves the implantation of a small device in the neck and chest via a surgical procedure. The device monitors the patient's breathing patterns during sleep and delivers a mild electrical stimulation to move the tongue forward with each breath. This action prevents the tongue from blocking the back of the throat, ensuring the upper airway remains open and maintaining smooth airflow. Compared to continuous positive airway pressure (CPAP) therapy, the most commonly recommended treatment for OSA, HGNS eliminates the need for patients to wear an external device, minimising discomfort and inconvenience. For further information, refer tothis article.

About the Device
Device Components

The device consists of three components fully implanted in the body:

  1. Generator in the chest
  2. Breathing sensing lead in the chest
  3. Nerve stimulation lead in the neck

A remote control is used to turn on or off the device when the patient is sleeping or waking up. Additionally, the patient can adjust the stimulation to the hypoglossal nerve according to their own comfort preferences.

remote control

The generator contains a battery that is replaced via a simple procedure under local anaesthesia approximately every 11 years. It is worth noting that the breathing sensing and nerve stimulation leads do not need to be changed.

Device implanted in the body

Device Outcomes

The device has been implanted in over 50,000 patients in the United States and Europe since its approval for use in 2014. One landmark study is the Stimulation Therapy for Apnea Reduction (STAR) trial, published in the New England Journal of Medicine in 2014. Subsequent studies have consistently shown significant improvement and/or cure of OSA, excellent compliance rates and high satisfaction among users over a five-year follow-up period. Sleepiness and quality of life measures have also shown marked improvement.

Some reported outcomes include:

  • 79% reduction in sleep apnea events1
  • 94% of patients are satisfied and would recommend it to family/friends2
  • 90% of bed partners reported soft or no snoring3

1,3 Woodson et al, Otolaryngol Head Neck Surg. 2018        
2 Heiser et al, Eur Respir J. 2019

Who is eligible to undergo this treatment?

Individuals who are at least 18 years old with moderate to severe OSA (AHI between 15-65 events/hour), and with a BMI of 32 or less. Patients who are unable to tolerate CPAP are usually recommended for this treatment. To assess eligibility, a sedated patient undergoes a drug-induced sleep endoscopy (DISE), a quick procedure where an ENT (ear, nose and throat) doctor uses a flexible nasoendoscope (camera) to assess how the airway collapses.

What can I expect during the surgery?

The surgical procedure typically lasts approximately two hours and is conducted under general anaesthesia. Two incisions will be made—one in the chest and another in the neck. These incisions will be covered with a dressing, which can be removed after two days.

What can I expect after the surgery?

Patients generally do not experience significant pain, although some soreness may be expected. Patients can return home on the same day of the surgery. After the surgery, patients can speak, swallow and shower as per usual and resume their regular diet. However, activities such as lifting heavy weights or vigorous exercises, especially those involving the upper body, should be avoided to allow the wounds sufficient time to heal.

What are the potential side effects?

The safety profile of this device has demonstrated excellence in numerous studies and real-world data. Non-serious side effects may include discomfort from the stimulation, temporary tongue weakness and wound swelling/infection. Device-related side effects, such as device migration or failure, are rare.

Contact Us

If you are interested in learning more about your eligibility for Hypoglossal Nerve Stimulation, please register your interest here. We will contact you within five working days.

Last updated on
Best viewed with Chrome 79.0, Edge 112.0, Firefox 61.0, Safari 11
National University Health System
  • National University Hospital
  • Ng Teng Fong General Hospital
  • Alexandra Hospital
  • Jurong Community Hospital
  • National University Polyclinics
  • Jurong Medical Centre
  • National University Cancer Institute, Singapore
  • National University Heart Centre, Singapore
  • National University Centre for Oral Health, Singapore
  • NUHS Diagnostics
  • NUHS Pharmacy
  • Yong Loo Lin School of Medicine
  • Faculty of Dentistry
  • Saw Swee Hock School of Public Health
Back to Top