BALTIMORE – Emerging developments for the treatment of obstructive sleep apnea have shown promise in providing options beyond continuous-positive airway pressure, investigators reported at the annual meeting of the Associated Professional Sleep Societies. These developments include a single-use nasopharyngeal airway stent, upper-airway stimulation using a pacemaker-like device, a negative-pressure device that opens the airway, and an artificial intelligence approach that can predict outcomes of oral appliance therapy.
Nasopharyngeal airway stent
Dr. Clete A. Kushida
Clete A. Kushida, MD, of Stanford (Calif.) University reported on recent results of a trial of the nasopharyngeal airway stent (NAS) single-use disposable insert (Seven Dreamers Laboratories, Tokyo). This device consists of a flexible semi-rigid silicone rubber tube 120-145 mm in length and coated with a hydrophilic gel. The patient inserts the distal end of the tube into the nostril, and it positions itself within the nasopharynx and retropalatal oropharynx to open the airway. A clip attaches to the exterior septum to keep the device in place. The patient removes the NAS in the morning. The device is commercially available in Japan and some European countries.
Dr. Kushida reported on two posters that were presented at Sleep 2018. The first by the Osaka University Graduate School of Dentistry in Japan investigated the predictability of NAS efficacy in patients with a velopharynx that was narrower than the hypopharynx (Sleep. 2018;41 (suppl 1):A207: doi.org/10.1093/sleep/zsy061.554). The study showed that 11 responders had a narrow velopharynx while 18 nonresponders had a narrow hypopharynx. Response was defined as 50% or greater reduction of apnea-hypopnea index (AHI) from baseline. “The success rate of NAS for the patients with narrowing of the velopharynx is 83.3%,” Dr. Kushida said.
He also reported on a study he led of NAS in patients with obstructive sleep apnea and healthy controls (Sleep. 2018;41 (suppl 1):A207: doi.org/10.1093/sleep/zsy061.555). The trial was conducted at Stanford and Tokyo sleep medical centers, with healthy controls at the Tokyo site only. AHI improved in all three obstructive sleep apnea (OSA) groups, but most significantly in those with moderate (n = 23) and severe (n = 21) OSA: 7.2 (P = .0038) and 11.7 (P = .0069), respectively. In the Stanford cohort, 2 of 32 patients originally enrolled dropped out because they found the NAS uncomfortable; none dropped out of the Tokyo cohort.
“NAS can be effective in treatment of snoring and OSA, in particular those with moderate/severe OSA, with significant improvement in mean obstructive apnea index,” Dr. Kushida said. He also noted the device is more effective in patients with narrowing of the oropharynx/velopharynx rather than the hypopharynx.
Dr. Kushida reported he had a financial relationship with the Seven Dreamers Laboratories.
Continuous negative external pressure
Jerrold A. Kram, MD, reported on a device that employs continuous negative external pressure – known as cNEP – that uses a silicone collar covering the front of the throat and a pump that applies suction to keep the airway open from the outside. He cited a small 2015 study out of Japan that found the device was effective in keeping the pharyngeal airway open in nonobese women (J Appl Physiol. 2015;118:912-20). Another small U.S. study found cNEP reduces respiratory impairment during screening colonoscopy (Endoscopy. 2016;48:584-7). Sommetrics, which has patented the technology, is developing a version of the product for obstructive sleep apnea, Dr. Kram said. The company already has a Food and Drug Administration–approved product to treat apneas that people experience when under mild to moderate sedation, such as a colonoscopy. It is approved for sale in Canada, but not in the United States.