The outcomes of hypoglossal nerve stimulation in the management of OSA: A systematic review and meta-analysis

The role of positional changes in optimizing OSA treatment: evidence from DISE

PURPOSE

This study aimed to assess the impact of positional changes on upper airway obstruction patterns during drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea (OSA) and identify the airway regions most responsive to this change. Special focus was placed on the tongue base, a critical area in OSA pathophysiology.

METHODS

This prospective study was conducted from June 2021 to June 2024. DISE was performed in patients with obstructive sleep apnea (OSA) in supine and lateral positions to simulate the effect of positional therapy. Findings were evaluated using the VOTE classification.

RESULTS

The examination was performed on 186 patients, with a median Apnea-Hypopnea Index (AHI) of 19.3. In the supine position, complete obstructions were noted at the soft palate (88.2%), oropharynx (33.3%), tongue base (53.2%), and epiglottis (15.6%). Lateral positioning significantly reduced obstructions, particularly at the tongue base, where obstruction resolved in 94/99 of cases (94.9%). This improvement was significantly more pronounced at the tongue base than at other sites (p < 0.001).

CONCLUSION

These results suggest that DISE can identify airway regions responsive to positional changes, potentially guiding clinical decisions on positional therapy. The findings show a significant reduction in tongue base obstruction during lateral positioning in DISE. Since tongue base obstruction is a key contributor to airway collapse in OSA, this improvement suggests a practical, non-invasive treatment approach. While these findings highlight an acute association between lateral positioning and reduced obstruction, further studies are needed to evaluate its long-term clinical efficacy.

Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea and Comorbid Neuromuscular Disorders

Hypoglossal nerve stimulation (HGNS) is an effective surgical treatment for many patients with moderate-to-severe obstructive sleep apnea (OSA) who are unable to tolerate continuous positive airway pressure. Patients with neuromuscular disorders (NMD) are particularly vulnerable to more complex sleep-related breathing disorders due to respiratory muscle weakness and the associated risk of hypoventilation. In this study, we present five patients with myasthenia gravis (n = 2), muscular dystrophy, Charcot-Marie-Tooth, and advanced multiple sclerosis who underwent HGNS therapy for OSA. At time of surgery, the mean patient age was 54 ± 18.7 years and mean BMI was 24.6 ± 4.6 kg/m2. Mean device adherence was 8 ± 1.1 h/night at three months and 7.2 ± 1.7 h/night at 12 months. Mean apnea-hypopnea index (AHI) improved significantly from preoperative baseline (34.9 to 8.5, p = 0.03) and 5/6 patients had a postoperative AHI <5. Epworth Sleepiness Scale scores significantly improved postoperatively (13.1-8.5, p = 0.03). Oxygen nadir trended upward (75.5-85.3, p = 0.84). Our limited findings demonstrate that HGNS was a safe and effective treatment for five patients with OSA and comorbid NMD. Prospective studies and larger sample sizes are warranted to support our findings and confirm whether HGNS is a potential therapeutic option for this unique patient population. Laryngoscope, 2025.

Are There Hidden Adverse Events in Hypoglossal Nerve Stimulation: Comparing Social Media and a Federal Database

OBJECTIVE

Hypoglossal nerve stimulation (HNS) can be an effective treatment for moderate to severe obstructive sleep apnea (OSA) in positive airway pressure (PAP) intolerant patients. To better understand patient experiences with HNS therapy, we explored reported events from HNS-related Facebook groups and the Manufacturer and User Facility Device Experience (MAUDE) database.

METHODS

A retrospective analysis of HNS-related Facebook posts from three groups pertaining to HNS therapy, from October 1, 2022 to October 1, 2023, was performed. Posts were analyzed for patient-reported adverse events. Concurrently, the MAUDE database was reviewed for HNS-related events during the same timeframe.

RESULTS

From 737 Facebook posts, 132 (17.55%) adverse events were identified. Adverse events included pain (34.85%), stimulation discomfort (14.39%), lip weakness (6.82%) and issues related to lead tethering or tight leads around the neck (3.79%). Analysis of the MAUDE database found 428 adverse events, including pain (24.07%), lip weakness (0.44%), and lead tethering (1.64%).

CONCLUSION

Facebook group members reported higher rates of lip weakness and lead tethering than recorded in the MAUDE database. These findings illustrate how diverse data sources, such as social media, can enhance our understanding of patient experiences and identify gaps in patient education with HNS therapy.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:5217-5222, 2024.

Outcome Reporting in Prospective Studies Evaluating Neurostimulation for Obstructive Sleep Apnea

OBJECTIVE

Due to the controversy surrounding the appropriate outcomes in neurostimulation, we sought to systematically describe ways in which polysomnography and apnea-hypopnea index are reported in prospective studies involving unilateral hypoglossal nerve stimulation.

DATA SOURCES

MEDLINE (Ovid), Embase (Ovid), Cochrane Library, and Scopus.

REVIEW METHODS

Following the Preferred Reporting items of Systematic Reviews and Meta-analysis (PRISMA) Statement guidelines, a systematic two-reviewer system was used for study screening and quality assessment. Articles that met inclusion criteria were included. Quality was evaluated with either the Newcastle-Ottawa Quality Assessment Scale or the Covidence risk-of-bias tool.

RESULTS

Fifteen studies met the inclusion criteria, which included 14 prospective cohort studies and one randomized controlled trial. Titration polysomnography was the primary sleep study used to acquire data in five of the studies compared to only three studies employing exclusively non-titration polysomnography to report outcomes. Three studies compiled data from two or more sleep studies to report a single apnea-hypopnea index. Within the 15 studies, non-titration apnea-hypopnea index was the most reported type (five studies). Titration apnea-hypopnea index was used to report outcomes in one study. Five studies did not specify what type of apnea-hypopnea index was employed to report treatment effectiveness.

CONCLUSION

The reported sleep studies and corresponding apnea-hypopnea indices were highly variable across the studies. Because of the high degree of heterogeneity, future research would benefit from consistent use of a standardized apnea-hypopnea index to report outcomes related to hypoglossal nerve stimulation.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:4873-4881, 2024.

[Ten years of hypoglossal nerve stimulation in obstructive sleep apnea: a systematic literature review]

OBJECTIVE

To show the importance of hypoglossal nerve stimulation (HGNS) as a treatment method for obstructive sleep apnea (OSA) in the German healthcare context and to better assess the way patients who do not receive adequate care could benefit from HGNS.

METHODS

A systematic literature review in the Medline and Cochrane Library literature database was conducted, including publications using different stimulation technologies for HGNS. The efficacy of HGNS was assessed based on patient-relevant outcomes (daytime sleepiness, quality of life), treatment adherence and the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). The safety of the treatment method was assessed based on adverse events (AEs).

RESULTS

Inclusion and analysis of 33 publications: 2 randomized controlled trials (RCTs, level Ib), 1 level IIb trial (n = 1) and 30 level IV trials with a study duration of up to 60 months. The RCTs showed better values for daytime sleepiness and quality of life when using HGNS than in the control group. AHI and ODI showed a deterioration under placebo stimulation or therapy withdrawal in the RCTs. Consistently high adherence was also reported in the long-term course. Severe AEs under HGNS were rare and could usually be resolved by repositioning electrodes or replacing device components. Other AEs were mostly transient or could be resolved by non-invasive measures. All investigated parameters showed similar results in the evaluated studies. The results of different stimulation systems are comparable in type and extent.

CONCLUSION

The comprehensive review of the literature shows consistent data that highlight the importance of HGNS as an effective and safe treatment for OSA after unsuccessful CPAP treatment. The evaluation also shows that the different stimulation systems make it possible to better tailor the therapy to the patient's individual requirements. A future systematic evaluation of real-world data on the use of HGNS would help gain additional insights into the relevance of the method in routine clinical practice.

Addressing the gaps: What social media tells us about patient experiences with hypoglossal nerve stimulation

PURPOSE

Hypoglossal nerve stimulation (HNS) can be an effective treatment for moderate to severe obstructive sleep apnea (OSA) in positive airway pressure (PAP) intolerant patients. To better understand patient perceptions of HNS therapy, we explored three Facebook groups pertaining to HNS therapy.

MATERIALS AND METHODS

A retrospective analysis of Facebook posts from three HNS-related Facebook groups, from October 1, 2022 to October 1, 2023, was performed. Posts were analyzed for author attitude, content (adverse events, inquiries, or sharing information), and the inclusion of media within the post.

RESULTS

From 737 Facebook posts, 752 events were identified, predominantly authored by patients or family (99.5 %). Few posts included media attachments (7.3 %), primarily photos (85.5 %). Post tone was mainly neutral (79.4 %), rather than positive (12.9 %) or negative (7.7 %). Most posts (53.6 %) were queries to the Facebook group, as opposed to sharing information (28.9 %) or detailing adverse events (17.6 %). Notably queries posed by Facebook group members included those pertaining to the postoperative recovery course (10.17 %), physical activity restrictions (6.20 %), HNS therapy eligibility (4.71 %), financial considerations (4.22 %), and more.

CONCLUSION

Overall, Facebook group members reported a predominantly neutral tone, typically posting queries to the group rather than sharing information or detailing adverse events. These findings illustrate how diverse data sources, such as social media, can enhance our understanding of patient experiences and identify gaps in patient education with HNS therapy.

Effect of norepinephrine reuptake inhibitors combined with antimuscarinic agents vs monotherapy for OSA: a systematic review and meta-analysis

STUDY OBJECTIVES

Randomized controlled trials have shown that combining norepinephrine reuptake inhibitors and antimuscarinics can ameliorate the severity of obstructive sleep apnea. This article explores whether the effectiveness and safety of combining norepinephrine reuptake inhibitors with antimuscarinic agents surpass monotherapy for treating obstructive sleep apnea.

METHODS

We searched randomized controlled trials including adult patients with obstructive sleep apnea who received combination therapy and monotherapy in 8 databases from inception until April 5, 2023 and evaluated the studies' quality and conducted a meta-analysis and systematic review. The primary outcome was the apnea-hypopnea index. Secondary outcome measures included loop gain, hypoxic burden, oxygen desaturation index, and ventilation at low ventilatory drive, among other indicators. We assessed the quality of the studies using Cochrane Methods criteria.

RESULTS

We identified 4 randomized controlled trials for systematic review and 2 for meta-analysis. The results of the meta-analysis showed that norepinephrine reuptake inhibitors combined with antimuscarinic agents in patients with obstructive sleep apnea prolonged total sleep time by a mean of 28.20 minutes [95% confidence interval (5.78, 50.61), P = .01] and increased sleep efficiency by 4.73% [95% confidence interval (0.50, 8.97), P = .03] compared with norepinephrine reuptake inhibitors alone. Other indices and adverse events were of no statistical significance. The systematic reviews revealed that norepinephrine reuptake inhibitors combined with antimuscarinics may be superior to monotherapy in improving apnea-hypopnea index and endotypic traits.

CONCLUSIONS

This evaluation demonstrated the potential advantages of combining norepinephrine reuptake inhibitors plus antimuscarinics for treating OSA compared with norepinephrine reuptake inhibitors alone and revealed no statistically significant difference in drug safety.

CITATION

Wang J, Ye Y, Shang Z, et al. Effect of norepinephrine reuptake inhibitors combined with antimuscarinic agents vs monotherapy for OSA: a systematic review and meta-analysis. J Clin Sleep Med. 2024;20(8):1363-1372.

Obstructive sleep apnoea in obesity: A review

Obstructive sleep apnea is a common comorbidity that occurs in individuals with obesity. It classically manifests with excessive daytime sleepiness, resulting in reduced quality of life, workplace productivity, and an increased risk of motor vehicle accidents. Weight gain plays an important role in its pathogenesis through worsening upper airway collapsibility, and current treatment options are targeted towards mechanically overcoming upper airway obstruction and weight loss. Continuous positive airway pressure therapy remains the most widely prescribed treatment for obstructive sleep apnea but poor tolerance is a common barrier to effective treatment. Sustainable weight loss is an important treatment option but can be difficult to achieve without bariatric surgery. The recent advances in incretin-based pharmacotherapies represent a promising avenue not only in achieving long-term weight loss but also in treating obstructive sleep apnoea and alleviating the burden of its symptoms and comorbidities.

Patient-reported experience with hypoglossal nerve stimulation in the treatment of obstructive sleep apnea

BACKGROUND

Breathing-synchronized hypoglossal nerve stimulation (HNS) is routinely used as an alternative treatment for patients with obstructive sleep apnea (OSA). Significant and clinically relevant improvements in disease severity and OSA symptoms such as daytime sleepiness as well as overall quality of life have been reported in randomized-controlled trials and large real-world cohort studies. However, so far, few data exist on patient-reported experience with the treatment.

METHODS

A structured survey with 22 questions was constructed using five-level Likert scales (1 = no agreement, 5 = complete agreement) to evaluate patient experience with HNS and perception of the treatment in the domains "Overall experience with therapy," "Experience with treatment process," and "Side-effects from treatment." Additional data were collected on current symptom status, measured with Epworth sleepiness scale (ESS) questionnaire, and OSA disease history. Multiple linear regression analysis was conducted to test associations of medical variables and response behavior. Correlations between variables and domains, as well as individual items, were assessed using Spearman rank test.

RESULTS

A total of 75 patients from Germany who were treated with breathing-synchronized HNS were enrolled (mean age 57.3 years, 78% male), and 71 questionnaires with complete data were included for analysis. Two-thirds of participants (67%) had a history of OSA history for 5 years or longer. Of all patients, 76% had normalized OSA symptoms at time of the study (ESS: 6.4 ± 5.0) and 98% reported using stimulation therapy every night. Regression analysis revealed an association of current symptoms measured with ESS and response behavior. Hence, patients with normalized daytime sleepiness reported significantly more positive experience across all domains assessed, compared to patients with residual daytime sleepiness. Overall, only 2% of participants reported side effects that made them reduce or discontinue stimulation therapy. The rate of reported side effects was associated with current symptom control under therapy.

CONCLUSIONS

Overall patient-reported experience with breathing-synchronized HNS therapy was positive and high satisfaction with the treatment process was observed. Side effects occurred, but rarely affected subjective use of the therapy or satisfaction. Subjective experience and perception are influenced by residual daytime sleepiness with stimulation therapy.

Hypoglossal Nerve Stimulation Effects on Obstructive Sleep Apnea Over Time: A Systematic Review and Meta-analysis

OBJECTIVES

This study aimed to determine the efficacy of hypoglossal nerve stimulation (HGS) in the treatment of obstructive sleep apnea.

DATA SOURCES

PubMed, Cochrane database, Embase, Web of Science, SCOPUS, and Google Scholar.

REVIEW METHODS

Five databases were reviewed to identify relevant studies that measured polysomnography parameters such as the apnea-hypopnea index (AHI) and oxygen desaturation index, as well as quality of life and functional outcomes of sleep questionnaire scores, before and after HGS.

RESULTS

In total, 44 studies involving 8670 patients met the inclusion criteria. At 12 months after treatment, approximately 47%, 72%, and 82% of patients achieved AHI values of <5, < 10, and <15, respectively. The reported clinical success rates according to Sher criteria were 80% within 12 months and 73% between 12 and 36 months. While the favorable effects exhibited a gradual reduction up to 12 months postimplantation, they generally maintained a consistent level between the 12th and 36th months, as assessed by AHI < 5, <15, and success rate according to Sher criteria.

CONCLUSION

HGS can enhance quality of life scores and polysomnography outcomes in obstructive sleep apnea patients. Although the positive effects gradually decreased until 12 months after implantation, they generally remained consistent between 12 and 36 months.

Snoring Patterns During Hypoglossal Nerve Stimulation Therapy Up-Titration

Longitudinal snoring changes can be captured using a mobile phone application. During hypoglossal nerve stimulator (HNS) therapy up-titration, increasing stimulation voltage was associated with reduced snoring frequency and intensity in this case series of six patients. Laryngoscope, 134:987-992, 2024.

Patient-reported outcomes with hypoglossal nerve stimulation for treatment of obstructive sleep apnea: a systematic review and meta-analysis

INTRODUCTION

Hypoglossal nerve stimulation (HNS) has recently been introduced as an alternative treatment for patients with OSA. A large number of studies have demonstrated substantial changes in OSA with this therapy by reducing respiratory events and improving symptoms such as daytime sleepiness and quality of life. The objective of this review was to conduct a systematic review and meta-analysis to evaluate patient-reported outcomes and experience with HNS therapy.

METHODS

A systematic literature search of MEDLINE, Cochrane, and Web of Science was performed to identify randomized controlled and observational studies reporting subjective outcomes with different HNS systems in patients with OSA. Abstracts of 406 articles were screened and a subset of 55 articles were reviewed for eligibility. Risk of bias was assessed using the ROBINS-I tool. Meta-analysis using RevMan was performed when > 2 studies were identified that reported data on a specific outcome.

RESULTS

Thirty-four publications reporting data on 3785 patients with a mean follow-up of 11.8 ± 12.2 months were identified and included in the meta-analysis. The analysis revealed a pooled effect of 4.59 points improvement in daytime sleepiness as measured by the ESS questionnaire (Z = 42.82, p < .001), 2.84 points improvement in daytime functioning as measured by the FOSQ score (Z = 28.38, p < .001), and 1.77 points improvement in sleep quality as measured by the PSQI questionnaire (Z = 2.53, p = .010). Patient-reported experience was consistently positive and revealed additional relevant aspects from this perspective.

CONCLUSION

HNS therapy significantly improves quality of life in patients with OSA and reliably produces clinically meaningful effects on daytime sleepiness, daytime functioning, and sleep quality. Treatment regularly meets or exceeds the minimum clinically important differences defined for the respective instruments. Additional research is needed to further investigate effects on quality of life beyond improvements in daytime sleepiness and daytime functioning.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Targeted Hypoglossal Nerve Stimulation for Patients With Obstructive Sleep Apnea: A Randomized Clinical Trial

Importance

Evidence is lacking from randomized clinical trials of hypoglossal nerve stimulation in obstructive sleep apnea (OSA).

Objective

To evaluate the safety and effectiveness of targeted hypoglossal nerve stimulation (THN) of the proximal hypoglossal nerve in patients with OSA.

Design, Setting, and Participants

This randomized clinical trial (THN3) was conducted at 20 centers and included 138 patients with moderate to severe OSA with an apnea-hypopnea index (AHI) of 20 to 65 events per hour and body mass index (calculated as weight in kilograms divided by height in meters squared) of 35 or less. The trial was conducted from May 2015 through June 2018. Data were analyzed from January 2022 through January 2023.

Intervention

Implant with THN system; randomized 2:1 to activation at month 1 (treatment) or month 4 (control). All received 11 months of THN with follow-up at months 12 and 15, respectively.

Main Outcomes and Measures

Primary effectiveness end points comprised AHI and oxygen desaturation index (ODI) responder rates (RRs). Treatment responses at months 4 and 12/15 were defined as a 50% or greater reduction in AHI to 20 or less per hour and an ODI decrease of 25% or greater. Coprimary end points comprised (1) month 4 AHI and ODI RR in the treatment greater than the control group and (2) month 12/15 AHI and ODI RR in the entire cohort exceeding 50%. Secondary end points included sleep apnea severity (AHI and ODI) and patient-reported outcomes (Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, and EQ-5D visual analog scale).

Results

Among 138 participants, the mean (SD) age was 56 (9) years, and 19 (13.8%) were women. Month 4 THN RRs were substantially greater in those in the treatment vs control group (AHI, 52.3% vs 19.6%; ODI, 62.5% vs 41.3%, respectively) with treatment-control standardized mean differences of 0.725 (95% CI, 0.360-1.163) and 0.434 (95% CI, 0.070-0.843) for AHI and ODI RRs, respectively. Months 12/15 RRs were 42.5% and 60.4% for AHI and ODI, respectively. Improvements in AHI, ODI, Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, and EQ-5D visual analog scale scores were all clinically meaningful (medium to large effect size). Two serious adverse events and 100 nonserious related adverse events were observed from the implant procedure or study protocol.

Conclusions and Relevance

This randomized clinical trial found that THN demonstrated improvements in sleep apnea, sleepiness, and quality of life in patients with OSAs over an extended AHI and body mass index range without prior knowledge of pharyngeal collapse pattern. Clinically meaningful improvements in AHI and patient-reported responses compared favorably with those of distal hypoglossal nerve stimulation trials, although clinically meaningful differences were not definitive for ODI.

Trial Registration

ClinicalTrials.gov Identifier: NCT02263859.

Quality of Life Impact of Hypoglossal Nerve Stimulation with Inspire® Device in Patients with Obstructive Sleep Apnea Intolerant to Continuous Positive Airway Pressure Therapy

Patients with obstructive sleep apnea (OSA) that do not tolerate/accept continuous positive airway pressure (CPAP) are candidates for surgical alternatives. Hypoglossal nerve stimulation (HNS) through the implantation of the Inspire® device constitutes a minimally invasive operative option. The main objective of this study is to estimate, under real-world clinical practice conditions, the 3-month impact on the quality of life (IQoL) of the HNS in patients with moderate/severe OSA who do not tolerate or accept CPAP, compared to patients who did not receive HNS. As a baseline, the unadjusted EuroQol utility index was 0.764 (SD:0.190) in the intervention group (IGr) and 0.733 (SD:0.205) in the control group (CGr); three months later, the indexes were 0.935 (SD: 0.101) and 0.727 (SD:0.200), respectively. The positive impact on quality of life was estimated to be +0.177 (95% CI: 0.044−0.310; p = 0.010). All dimensions in the IGr improved compared to CGr, especially for usual activities (p < 0.001) and anxiety/depression (p > 0.001). At the end of the follow-up, there was no significant difference in the quality of life between the general Spanish population and the IGr (difference: 0.012; CI95%: −0.03 to −0.057; p = 0.0578) for the same age range; however, there was a difference concerning the CGr (difference: −0.196; CI95%: −0.257 to −0.135; p < 0.001). In conclusion, patients with moderate/severe OSA implanted with the Inspire® device showed a positive IQoL.

Hypoglossal nerve stimulator patient usage: Patterns and trends over time

Objective

Hypoglossal nerve stimulation (HNS) is an effective treatment for obstructive sleep apnea (OSA) patients intolerant of continuous positive airway pressure but is only effective if used regularly. Usage patterns have not been studied in detail. In this study, we aimed to characterize granular HNS usage patterns.

Methods

Patients implanted by a single surgeon at an academic medical center from August 2016 to January 2021 were identified from a prospective database, which was merged with the Inspire Cloud usage database. Patient, OSA, and usage characteristics were summarized, and patient- and OSA-related characteristics were associated with usage characteristics by Wilcoxon rank-sum analyses. Usage trends over time were summarized in the overall cohort and stratified by initial usage.

Results

Fifty patients were included. Median usage was 94% of nights (interquartile range [IQR]: 82%-98%) for 5.8 h per night (IQR: 4.9-6.4). Higher post-operative apnea-hypopnea index predicted fewer nights used (92% [IQR: 82%-97%] vs. 96% [IQR: 91%-99%]). No other characteristics examined were significantly associated with usage. Median hours used per night decreased from 6.80 h (IQR: 5.32-7.94) on Day 1 to 5.76 (IQR: 1.81-7.13) on Day 361. This decrease was most pronounced in the quartile with the lowest initial usage.

Conclusion

This study found that most patient and OSA characteristics were not associated with HNS usage, and that usage generally decreased over time. This decrease in usage over time was most pronounced in patients with the lowest initial usage. Further work should identify interventions to improve usage patterns to optimize clinical outcomes. Level of Evidence: 4.

An Update on Obstructive Sleep Apnea for Atherosclerosis: Mechanism, Diagnosis, and Treatment

The occurrence and development of atherosclerosis could be influenced by intermittent hypoxia. Obstructive sleep apnea (OSA), characterized by intermittent hypoxia, is world-wide prevalence with increasing morbidity and mortality rates. Researches remain focused on the study of its mechanism and improvement of diagnosis and treatment. However, the underlying mechanism is complex, and the best practice for OSA diagnosis and treatment considering atherosclerosis and related cardiovascular diseases is still debatable. In this review, we provided an update on research in OSA in the last 5 years with regard to atherosclerosis. The processes of inflammation, oxidative stress, autonomic nervous system activation, vascular dysfunction, platelet activation, metabolite dysfunction, small molecule RNA regulation, and the cardioprotective occurrence was discussed. Additionally, improved diagnosis such as, the utilized of portable device, and treatment especially with inconsistent results in continuous positive airway pressure and mandibular advancement devices were illustrated in detail. Therefore, further fundamental and clinical research should be carried out for a better understanding the deep interaction between OSA and atherosclerosis, as well as the suggestion of newer diagnostic and treatment options.

Clinical and Research Solutions to Manage Obstructive Sleep Apnea: A Review

Obstructive sleep apnea (OSA), a common sleep disorder disease, affects millions of people. Without appropriate treatment, this disease can provoke several health-related risks including stroke and sudden death. A variety of treatments have been introduced to relieve OSA. The main present clinical treatments and undertaken research activities to improve the success rate of OSA were covered in this paper. Additionally, guidelines on choosing a suitable treatment based on scientific evidence and objective comparison were provided. This review paper specifically elaborated the clinically offered managements as well as the research activities to better treat OSA. We analyzed the methodology of each diagnostic and treatment method, the success rate, and the economic burden on the world. This review paper provided an evidence-based comparison of each treatment to guide patients and physicians, but there are some limitations that would affect the comparison result. Future research should consider the consistent follow-up period and a sufficient number of samples. With the development of implantable medical devices, hypoglossal nerve stimulation systems will be designed to be smart and miniature and one of the potential upcoming research topics. The transcutaneous electrical stimulation as a non-invasive potential treatment would be further investigated in a clinical setting. Meanwhile, no treatment can cure OSA due to the complicated etiology. To maximize the treatment success of OSA, a multidisciplinary and integrated management would be considered in the future.

The Hypoglossal Nerve Stimulation as a Novel Therapy for Treating Obstructive Sleep Apnea-A Literature Review

Obstructive sleep apnea (OSA) is a common sleep disorder that affects all age groups and is associated with many co-morbid diseases (especially cardiovascular diseases). Continuous positive airway pressure (CPAP) is the gold standard for treating OSA. However, adherence to PAP therapy has been a major challenge with an estimated adherence between 20% and 80%. Mandibular advancement devices (MAD) are a good alternative option if used in the appropriate patient. MAD are most effective in mild and moderate OSA but not severe OSA. Surgical options are invasive, not appropriate for severe OSA, and associated with pain and long healing time. Hypoglossal nerve stimulation (HGNS), or upper airway stimulation (UAS), is a novel therapy in treating moderate and severe degrees of OSA in patients who cannot tolerate CPAP therapy. We reviewed the MEDLINE (PubMed) database. The search process yielded 303 articles; 31 met the inclusion and exclusion criteria and were included. We concluded that hypoglossal nerve stimulation is a very effective and novel alternative therapy for moderate and severe OSA in patients who cannot tolerate CPAP therapy. Adherence to HGNS is superior to CPAP. However, more developments are needed to ensure the highest safety profile.

Considering the Role of Adherence in New and Emerging Sleep Treatments

There are several novel and emerging treatments for obstructive sleep apnea (OSA), including new devices and pharmacotherapies. Long-term efficacy and adherence data for these interventions in the sleep context are lacking. Future studies exploring the long-term adherence and efficacy in novel and emerging treatments of OSA are required to fully understand the place of these treatments in treatment hierarchies. Such research also should aim to evaluate the use of these novel therapies in real-world clinical settings, because many of the studies performed to date have been done under closely monitored research populations and relatively small sample sizes.

Maxillomandibular Advancement and Upper Airway Stimulation: Extrapharyngeal Surgery for Obstructive Sleep Apnea

There are many ways to categorize surgery for obstructive sleep apnea (OSA), one of which is to distinguish between intrapharyngeal and extrapharyngeal procedures. While the general otolaryngologist treating OSA is familiar with intrapharyngeal procedures, such as uvulopalatopharyngoplasty and tongue base reduction, extrapharyngeal sleep operations such as maxillomandibular advancement (MMA) and upper airway stimulation (UAS) have evolved rapidly in the recent decade and deserve a dedicated review. MMA and UAS have both shown predictable high success rates with low morbidity. Each approach has unique strengths and limitations, and for the most complex of OSA patients, the two in combination complement each other. Extrapharyngeal airway operations are critical for achieving favorable outcomes for sleep surgeons.

Assessment and Management of Postoperative Pain Associated with Sleep Apnea Surgery

A literature review was conducted regarding the assessment and treatment of postoperative pain following surgery for obstructive sleep apnea (OSA). Given the risks of opioid use by patients with OSA, special attention to opioid risk reduction and avoidance is warranted in this population. The results of this review demonstrate the existence of a body of evidence that supports the use of nonopioid analgesics and nonpharmacologic approaches pain management. Strategies for managing postoperative pain should emphasize the use of local anesthetic infiltration, nonsteroidal antiinflammatory drugs, acetaminophen, topical analgesics, surgical wound cooling, and when necessary, safer opioid medications, such as tramadol and intranasal butorphanol.

Electrical stimulation as a therapeutic approach in obstructive sleep apnea - a meta-analysis

PURPOSE

Electrical stimulation of the upper airway dilator muscles is an emerging treatment for obstructive sleep apnea (OSA). Invasive hypoglossal nerve stimulation (HNS) has been accepted as treatment alternative to continuous positive airway pressure (CPAP) for selected patients, while transcutaneous electrical stimulation (TES) of the upper airway is being investigated as non-invasive alternative.

METHODS

A meta-analysis (CRD42017074674) on the effects of both HNS and TES on the apnea-hypopnea index (AHI) and the Epworth Sleepiness Scale (ESS) in OSA was conducted including published evidence up to May 2018. Random-effects models were used. Heterogeneity and between-study variance were assessed by I² and τ², respectively.

RESULTS

Of 41 identified clinical trials, 20 interventional trials (n = 895) could be pooled in a meta-analysis (15 HNS [n = 808], 5 TES [n = 87]). Middle-aged (mean ± SD 56.9 ± 5.5 years) and overweight (body mass index 29.1 ± 1.5 kg/m²) patients with severe OSA (AHI 37.5 ± 7.0/h) were followed-up for 6.9 ± 4.0 months (HNS) and 0.2 ± 0.4 months (TES), respectively. The AHI improved by - 24.9 h^-1 [95%CI - 28.5, - 21.2] in HNS (χ² 79%, I² 82%) and by - 16.5 h^-1 [95%CI - 25.1, - 7.8] in TES (χ² 7%, I² 43%; both p < 0.001). The ESS was reduced by - 5.0 (95%CI - 5.9, - 4.1) (p < 0.001).

CONCLUSION

Both invasive and transcutaneous electrical stimulation reduce OSA severity by a clinically relevant margin. HNS results in a clinically relevant improvement of symptoms. While HNS represents an invasive treatment for selected patients with moderate to severe OSA, TES should be further investigated as potential non-invasive approach for OSA.

Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

Purpose

This review will trace the elements of neurostimulation for obstructive sleep apnea and details on its implementation, efficacy and safety, immediate clinical outcomes, and future prospects.

Methods

The literature on upper airway neurostimulation was surveyed from July, 2013, to July 2019, with a focus on the components of devices, evidence for clinical utility, and adverse events.

Results

Current technology is focused on the hypoglossal nerve stimulation (HNS). The most long-term experience is with the Inspire Medical System (Maple Grove, MN USA) which has both FDA and European regulatory approval. Given the inclusion criteria (BMI <35, ideally <32), AHI 15-65/h, and a favorable anterior-posterior velopharyngeal collapse pattern on DISE), across many centers ~65% of patients who are intolerant to primary therapy achieve clinical success (AHI <20/h with a reduction of <50% in AHI), and more have symptomatic relief. Adverse events are generally mild, often self-limited, with occasional need for uncomplicated surgical adjustments or replacement of the implantable generator. Three other devices are in various phases of development, each with a differences in nerve electrodes, implantable components, power sources, proprietary programming, and activation patterns.

Conclusions

HNS is not considered a first-line treatment option. HNS therapy, however, should be considered as one alternative therapeutic option for patients meeting the inclusion criteria when more traditional therapeutic options have been considered.

The specific branches leading to the genioglossus muscle: three-dimensional localisation using skin reference points

INTRODUCTION

Supra-selective stimulation of the branches destined for the horizontal part of genioglossus muscle (GGh) could be a target of choice in the treatment of mild-to-severe obstructive sleep apnea syndrome. The main aim of our study was to assess a percutaneous method for the three-dimensional localisation of the terminal branches destined to GGh.

MATERIALS AND METHODS

Twenty cadaveric hypoglossal nerves were dissected and included in the injection protocol. The distance between the posterior edge of the mandibular symphysis and the hyoid bone on the sagittal midline as the approximated distance of the geniohyoid muscle (dGH) was measured before any dissection. Methylene blue mixed with a thickening agent, was injected. The injection point was defined in relation to dGH, in an orthonormal coordinate system. For each dissection, we recorded the theoretical and the real (X, Y, Z) coordinates of GGh motor points and measured their distance to each other.

RESULTS

X was accurately estimated. Y and Z were overestimated by + 5.34 ± 5.21 mm ([Formula: see text]) and + 4.79 ± 3.99 mm ([Formula: see text]) on average, respectively. We found a more significant difference between the theoretical and real Y and Z coordinates in the subgroup BMI < 25 kg/m² (8.6 ± 4.5 mm and 6.9 ± 2.5 mm, respectively, p = 0.0009), and of Z in subgroup with dGH ≥ 50 mm (6.89 ± 3.26 mm, p = 0.0494).

CONCLUSIONS

X can be estimated accurately using the relationship [Formula: see text]. Y seems to be related to BMI and Z may be estimated with the relationship [Formula: see text]. This three-dimensional localisation could be very helpful to facilitate placement of cuff electrodes to manage refractory sleep apnea.

Inclusion of the first cervical nerve does not influence outcomes in upper airway stimulation for treatment of obstructive sleep apnea

OBJECTIVES/HYPOTHESIS

Upper airway stimulation (UAS) has demonstrated efficacy in the management of obstructive sleep apnea (OSA). Branches of the hypoglossal nerve that selectively activate tongue protrusor and stiffener muscles are included within the stimulation cuff electrode. The first cervical nerve (C1) is often also included to stimulate additional muscles contributing to tongue protrusion and stabilization. The purpose of this study was to determine whether inclusion of the C1 translates into treatment efficacy, decreased voltage requirement, and improved outcomes in patients utilizing UAS.

STUDY DESIGN

Single-center, retrospective cohort study.

METHODS

One hundred fourteen patients who received a UAS implant at our institution and underwent posttreatment polysomnography were evaluated. Stimulation cuff electrodes in 87 patients included the C1; those in the remaining 27 patients did not include the C1. Demographic data, voltage data, and pre- and posttreatment apnea-hypopnea index (AHI), O₂ nadir, and Epworth Sleepiness Scale (ESS) data were collected for all patients.

RESULTS

There was no significant difference in stimulation voltage, or posttreatment AHI, O₂ nadir, and ESS between the two cohorts. Treatment success, as measured by posttreatment AHI < 20 with a 50% reduction, was similar regardless of C1 inclusion. The same was seen for the percent of patients with AHI < 15 and AHI < 5 after treatment. The distributions of age and body mass index, as well as pre-treatment AHI, O₂ nadir, and ESS were also not significantly different between treatment groups.

CONCLUSIONS

The current study has demonstrated that inclusion of the C1 in the stimulation cuff electrode of the upper airway stimulator may not provide any additional benefit in therapy for OSA.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E382-E385, 2020.

Sleep Disorders and Stroke: Does Treatment of Obstructive Sleep Apnea Decrease Risk of Ischemic Stroke?

PURPOSE OF REVIEW

This review aims to support obstructive sleep apnea (OSA) as a risk factor for ischemic stroke, review treatment strategies for OSA, provide a comprehensive review of clinical data on OSA treatment and ischemic stroke risk, and to critically assess if treatment of OSA decreases the risk of ischemic stroke and if treatment improves outcomes and subsequent ischemic stroke risk in post-stroke patients.

RECENT FINDINGS

Several observational studies, randomized controlled trials (RCTs), and meta-analyses have examined the risk of ischemic stroke and cardiovascular events in patients with OSA and have also examined continuous positive airway pressure (CPAP) treatment in these patients. Observational studies have shown an increased risk of ischemic stroke in patients with untreated OSA when compared with patients treated with CPAP; however, results are not statistically significant. RCTs and meta-analyses have shown no significant ischemic stroke risk reduction in CPAP treated patients with OSA. Several studies have shown improved outcomes in post-stroke patients with OSA treated with CPAP; however, few data is available for subsequent ischemic stroke risk reduction. Further research is needed for surgical treatment of OSA and assessment of ischemic stroke risk. OSA is associated with increased risk of ischemic stroke, and OSA should be treated with the appropriate therapy. While the current data is promising, more studies are necessary to state whether treatment of OSA reduces ischemic stroke risk and subsequent ischemic stroke risk. A practical approach to the sleep disorder evaluation and treatment of patients with cerebrovascular disease is outlined.