Hypoglossal nerve stimulation (HGNS) is a new and alternative sleep disorder treatment which is available in Singapore in 2023. It stimulates the hypoglossal nerve to address obstructive sleep apnea, an often-found disorder which causes difficulty breathing and snoring while sleeping. FDA-approved in 2014, HGNS offers some people an alternative to positive airway pressure therapy for those suffering from this condition.
Hypoglossal nerve stimulation surgery is a surgical procedure that involves implanting a medical device in the chest to stimulate the hypoglossal nerve with rhythmic electrical pulses synchronized with breathing. HGNS is considered safe and effective for people suffering from obstructive sleep apnea who cannot tolerate continuous positive airway pressure.
The HGNS system consists of an implanted cuff that surrounds the HGN, an implanted pulse generator in the interventricular space and an implanted sensor lead in the intercostal space. The pulse generator delivers electrical stimulation to selected HGN fibers within the cuff in coordination with respiration as detected by the sensor lead.
Once the pulse is received, it causes the tongue to move forward and clears airway obstruction. This reduces obstructive episodes in those with sleep apnea and improves their quality of sleep.
In the STAR trial, HGNS use resulted in significant improvements to sleep quality and reductions in both apnea-hypopnea index and oxygen desaturations. These findings have been confirmed by numerous other studies, making HGNS the go-to solution for treating obstructive sleep apnea among those who cannot tolerate or decline CPAP therapy.
To maximize the effectiveness of HGNS therapy, it is important to optimize both device settings and patient factors that affect titration. Factors such as patient age, health status, and psychological conditions can all influence therapy response; thus, a better understanding of these variables will allow us to expand indications for HGNS beyond older or obese individuals.
This HGNS procedure calls for two incisions on the upper chest, each measuring 5 cm long. The first incision is made at the sternum while the second one is situated along the mid-clavicular line.
In the initial incision, a flap of skin is taken from the sternum to expose the cuff. The cuff is then wrapped around the HGNS and secured with suture thread before stitching it in place. Finally, an electrode is placed over the cuff to monitor HGNS activity during surgery.
A second incision is made in the upper chest, about 3 cm below the clavicle. The cuff is then secured inside with suture thread for extra security.
The cuff can be adjusted for various stimulation parameters using a computer-controlled programmer and remote. Three key parameters to consider when programming stimulation parameters are duty cycle (length of stimulus train), amplitude (energy output), and pulse frequency (interval between pulses). These settings can be fine-tuned by your doctor to achieve the optimal effect.
Conducting HGNS surgery necessitates the expertise of an experienced plastic surgeon with expertise in both otolaryngology and neurotology. A multidisciplinary team comprised of a plastic surgeon, an ENT or otolaryngologist, and an anesthesiologist is necessary for safety during this procedure. Consult your doctor or Easmed in Singapore for more details about HGNS.
