A new method of stimulating the hypoglossal nerve can improve outcomes for patients with obstructive sleep apnea, according to a recent randomized control trial published in Annals of Internal Medicine, broadening the number of treatment options available for individuals unable to tolerate continuous positive airway pressure (CPAP).

Nearly 60% of participants treated with a proximal nerve stimulator (LivaNova’s aura6000) experienced a 50% or greater improvement in their baseline apnea-hypopnea index scores, a measure of the number of times breathing stops or is significantly obstructed during sleep.

“Hypoglossal nerve stimulation is a relatively new treatment for obstructive sleep apnea, and we’ve only had really one player on the block,” called Inspire (Inspire Medical Systems), said Eric Landsness, MD, PhD, an assistant professor of neurology at Washington University School of Medicine in St. Louis. “This is an exciting alternative.”

Nearly 84 million adults have obstructive sleep apnea in the US, with 48% of those living with moderate or severe cases. While CPAP is the first line of treatment, many people do not tolerate this treatment.

The trial included adults aged 22 years or older who had a BMI of 35 or lower, moderate-to-severe sleep apnea, and were unable to tolerate the CPAP. Enrolled at 23 clinics starting in 2021, participants underwent surgery for device implantation (n = 104), but the device was initially only turned on for those in the treatment group (n = 67).

After 7 months of device use, 58.2% of patients in the treatment group showed an improvement in their scores for apnea-hypopnea index scores by at least 50% or more from their baseline (P < .05). In the control group, 13.5% saw this improvement (P < .05).

Both groups used the device for an additional 5 months, with the treatment group showing superior improvement in apnea and hypopnea.

Patients’ oxygen desaturation was also measured. Two thirds of those in the treatment group showed improvement in oxygen scores by at least 25% from their baseline compared to one third of those in the control group (P < .05).

Other Considerations

Stimulating devices such as Inspire and Genio have been on the market since 2014, but target the distal portion, or branches, of the hypoglossal nerve. The aura6000 targets the proximal portion, or trunk, of the same nerve.

Both types of devices are placed in the upper chest with sensors extending to the neck. A generator sends pulses to the hypoglossal nerve to better position the tongue, lessening airway obstruction during sleep. The proximal stimulation device, however, is less invasive and less time intensive to implant, said Atul Malhotra, MD, a professor of medicine and sleep medicine specialist at UC San Diego Health in San Diego, who led the study.

The proximal part of the nerve “is sort of closer to the skin. You can almost see it from the second you open the skin,” while the distal part of the nerve is buried and entails digging during the procedure, Malhotra said.

Patients who receive distal nerve stimulation devices typically must undergo a drug-induced sleep endoscopy as a condition for treatment, Malhotra said. But patients in the trial did not receive this procedure for the new device, nor will they in clinical settings, he said.

Eliminating the need for endoscopy may reduce attrition from long wait times and expand access to treatment for patients previously excluded from distal hypoglossal nerve stimulation due to complete concentric collapse identified during endoscopy, Landsness said.

“To go through the pathway from initial evaluation to referral to an ear, nose, and throat specialist, to actually going through the [endoscopy] procedure, to then going through surgery, then device activation — all this sometimes, on average, takes 6 months,” for the distal implant, Landsness said.

Implantation of hypoglossal nerve stimulation is one of many procedures that require prior authorization under Medicare’s WISeR program, which began testing in six states in January. Malhotra said he understands why this procedure is on the list, given its cost ranging from $30,000 to $40,000, while the CPAP is readily available and much cheaper.

“If people were trigger happy going to a surgical approach before trying other established medical approaches, you can break the bank quite quickly. So I think it is wise to be cautious about who should get a surgical treatment or not,” he said.

CPAP should still be the first line of treatment, but for people who cannot tolerate the mask because of claustrophobia or discomfort, nerve stimulation is the next best option, Malhotra said.

Landsness cautioned that a 58% response rate for the new implant is still relatively low.

“We need to better understand and predict who is going to respond to these treatments or not,” he said.

Malhotra reported receiving grant funding for this research from LivaNova, and he is a paid consult for LivaNova and Eli Lilly. Landsness reported having no relevant financial disclosures.

Kelsey Mesmer, PhD, is a freelance journalist and journalism professor at Saint Louis University in St. Louis.