HSC Section 3 - Trauma, Critical Care and Sleep Medicine

Fig. 1. Median apnea-hypopnea index (A) and oxygen desaturation index (B) over 36-month follow-up after implantation of upper airway stimulation.

Fig. 2. Median Functional Outcome of Sleep Questionnaire (A) and Epworth Sleepiness Scale (B) over 36-month follow-up after implantation of upper airway stimulation.

72% of subjects had resolution of discomfort with alter- ation of the stimulation; 8% improved with the addition of an acrylic tooth guard to reduce abrasion, and 20% reported reduced discomfort with ongoing device use and acclimation. Adherence was excellent by self-report (86% of participants using the therapy nightly at the 12-month mark), but detailed objective data monitoring was limited. At 12 months, a randomized therapy withdrawal study was performed in the first 46 responders. As with CPAP withdrawal studies, this study demonstrated that withdrawal of hypoglossal nerve stimulation (HNS) ther- apy resulted in a recurrence of OSA severity, daytime sleepiness, and impaired quality of life. These results emphasize that, similar to CPAP, nightly use of the ther- apy is required to maintain effectiveness. STAR Follow-up Results Additional studies on long-term outcomes have since been published from the STAR Trial. At 18 months follow-up, polysomnographic outcome measures were maintained without an increase of the stimulation thresholds or tongue injury. 39 At 24 months follow-up, upper airway stimulation was reported to provide clini- cally meaningful and statistically significant improve- ments in patient-centered OSA outcome measures, including snoring, daytime sleepiness, and sleep-related quality of life. 40 The effect size on patient-centered out- come measures was also large and compared favorably

to CPAP as well as other second-line therapies. Finally, the significant improvements AHI and ODI (Fig. 1) were maintained at 3 years in addition to ongoing significant improvements in sleepiness, sleep-related quality of life, and snoring (Figs. 2 and 3), with minimal variation due to the study sample sizes, night-to-night polysomno- gram, and minor stimulation adjustments in some indi- viduals. 41 Of the 126 originally implanted subjects, 116 participants (92%) completed the scheduled 36-month clinical follow-up, and 98 participants (78%) completed a voluntary 36-month polysomnogram. For the group undergoing the 36-month polysomnogram, 74% met responder status, with 87% of subjects using the device at least 5 nights per week. 41

Fig. 3. Change in snoring intensity as rated by bed partner during 36 months of follow-up after implantation of upper airway stimulation.

Soose and Gillespie: Upper Airway Stimulation Therapy

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