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Upper airway stimulation appeared safe and effective in improving severe persistent obstructive sleep apnea (OSA) in adolescents with Down syndrome, a small multi-center cohort study found.

In this first study to evaluate upper airway hypoglossal stimulation in a pediatric population, polysomnographic and quality-of-life outcomes improved significantly 1 year after the implant of an upper airway stimulation device.

High adherence to the therapy was also reported in this population by Phoebe K. Yu, MD, MPH, of Massachusetts Eye and Ear in Boston, and colleagues in .

Overall, the 42 patients in the study (28 male, mean age 15.1) had a mean decrease in apnea-hypopnea index (AHI) of 12.9 events per hour. At 12 months, 66% demonstrated a response to therapy -- defined as at least a 50% reduction in AHI -- and 73% of patients dropped below 10 events per hour.

In addition, therapy was safe, with none of the patients requiring removal of the device or developing long-standing morbidity following surgery.

"Patients with Down syndrome, persistent OSA after adenotonsillectomy, and PAP [positive airway pressure] intolerance have limited therapy options and are at risk for health complications from untreated disease," Yu and her fellow study authors explained. "Although there was a high overall therapy response rate, most patients in our study still had an AHI of more than 5 events/hour at the end of the study, or residual moderate sleep apnea."

Patients also reported subjective improvement in daytime sleepiness and quality of life, with mean improvements of 5.1 (95% CI -7.4 to -2.8) in the Epworth Sleepiness Scale score for daytime sleepiness and 34.8 (95% CI -42.1 to -27.5) in the Obstructive Sleep Apnea (OSA-18) survey of effects on sleep disorders, physical distress, emotional distress, diurnal problems, and caretaker occupation.

Importantly, 95% of patients used the device for at least 4 hours a night, the group reported. Overall, "the mean nightly duration of ... therapy was approximately 9 hours, which is tremendous given that children with sensory disorders were not excluded," wrote Norman R. Friedman, MD, and Katherine K. Green, MD, MS, both of Children's Hospital Colorado in Aurora, in an invited .

All patients received hypoglossal nerve stimulator implant without intraoperative complications or subsequent removal of the device. Temporary tongue or oral discomfort was the most common complication, affecting 12% (five of 42) of patients, and two required an additional surgery.

Some patients required device titration, even a year after surgery. One reason was the gradual device titration required by the safety protocol for this pediatric population, an approach that "may improve tolerance of therapy," the editorialists suggested.

While the treatment response rate observed in this study was comparable to the 63-66% noted in initial and adult studies, the editorialists cautioned that OSA severity criteria for children and adults differ, with an AHI of 10 or more events/hour considered severe in children, versus the threshold of 15 events/hour for moderate OSA in adults. This is particularly relevant "because two-thirds of children with Down syndrome experience persistent moderate or severe pediatric OSA after UAS [upper airway stimulation]," they wrote.

For those children, the editorialists suggested that "... include confirming proper system function, device reprogramming, and consideration of adjunct treatments with UAS, including positional therapy, concurrent use of a mandibular advancement device, or the addition of supplemental oxygen via nasal cannula."

"Although UAS surgery is safe from an assessment of perioperative risks, identifying which children are the best candidates for an implant is still a mystery," Friedman and Green noted. Given the differences in physiologic endotype of sleep apnea and demographic characteristics in children versus adults, they urged caution in extrapolating "factors associated with the success and limitations of therapy."

That the readmission rate in these young Down syndrome patients exceeded that previously reported in adult studies might be explained by "the low threshold for readmission for a high-risk pediatric population," Yu's group noted, as well as the increased risk of patients picking at surgical incisions, which is an important consideration "in preoperative patient selection and family counseling."

Researchers noted that limitations included the lack of an untreated control group, the inclusion of some young adult patients older than age 18, variations in sleep study reports regarding time with oxygen saturation below 88% versus 90%, the small sample size, and the inability to identify any prognostic factors in this population.

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