Effect of upper-airway stimulation for obstructive sleep apnoea on airway dimensions

Abstract

Upper-airway stimulation (UAS) using a unilateral implantable neurostimulator for the hypoglossal nerve is an effective therapy for obstructive sleep apnoea patients with continuous positive airway pressure intolerance. This study evaluated stimulation effects on retropalatal and retrolingual dimensions during drug-induced sedation compared with wakefulness to assess mechanistic relationships in response to UAS.Patients with an implanted stimulator underwent nasal video endoscopy while awake and/or during drug-induced sedation in the supine position. The cross-sectional area, anterior-posterior and lateral dimensions of the retropalatal and retrolingual regions were measured during baseline and stimulation.15 patients underwent endoscopy while awake and 12 underwent drug-induced sedation endoscopy. Increased levels of stimulation were associated with increased area of both the retropalatal and retrolingual regions. During wakefulness, a therapeutic level of stimulation increased the retropalatal area by 56.4% ( p=0.002) and retrolingual area by 184.1% ( p=0.006). During stimulation, the retropalatal area enlarged in the anterior-posterior dimension while retrolingual area enlarged in both anterior-posterior and lateral dimensions. During drug-induced sedation endoscopy, the same stimulation increased the retropalatal area by 180.0% ( p=0.002) and retrolingual area by 130.1% ( p=0.008). Therapy responders had larger retropalatal enlargement with stimulation than nonresponders.UAS increases both the retropalatal and retrolingual areas. This multilevel enlargement may explain reductions of the apnoea-hypopnoea index in selected patients receiving this therapy. @ERSpublications Upper-airway stimulation for OSA increases airway dimensions at both the tongue base and the palate

Upper Airway Stimulation for Obstructive Sleep Apnea: Self-Reported Outcomes at 24 Months

“…In patients with moderate to severe OSA and specific clinical and anatomical characteristics, UAS therapy has previously been shown to provide multilevel (retropalatal and retrolingual) improvement in airway dimension and airflow by augmenting neuromuscular function of specific upper airway muscles while avoiding anatomy-altering surgery -dramatically reducing side effects, recovery, and risk. [21][22][23] Prior reports have also demonstrated significant and sustained reductions in polysomnographic measures of OSA severity over a 12-to 18-mo follow-up period. 7,8 At 18 mo, the median apnea-hypopnea index (AHI) was reduced by 67.4% from the baseline of 29.3 to 9.7/h, and the median 4% oxygen desaturation index (ODI) was reduced by 67.5% from 25.4 to 8.6/h.…”

Functional outcome of tongue motions with selective hypoglossal nerve stimulation in patients with obstructive sleep apnea

“…Recently, Safiruddin et al showed that unilateral stimulation of the hypoglossal nerve increases airway area at multiple levels [39]. The degree of UA opening corresponded to higher amplitudes of stimulation.…”

“…In most patients with a higher AHI, the obstructions are found on different levels such as the tongue base and the retropalatal region. Most importantly, opening the airway in an anterior-posterior dimension during hypoglossal nerve stimulation is relevant particularly concerning the role of airway shape for OSA therapies [39].…”

Endoscopic upper airway evaluation in obstructive sleep apnea: Mueller’s maneuver versus simulation of snoring

“…ImageJ was used in another study describing upper airway crosssectional area very recently [18]. One co-investigator who was blinded to the AG results analyzed each image five times, and the mean was calculated.…”