Pediatric Down Syndrome Upper Airway Stimulation: Patient Selection and Post-Implantation Optimization

OBJECTIVE

The Food and Drug Administration recently approved upper airway stimulation (UAS) for children with Down Syndrome and persistent obstructive sleep apnea who meet certain inclusion and exclusion criteria. Although there is a robust experience with this therapy in the adult population, established protocols used in adults are not directly transferrable to a complex pediatric population. This review aims to combine the protocols from several institutions for patient selection and postimplantation optimization, including a protocol for Drug-Induced Sleep Endoscopy in children with Down Syndrome, preactivation threshold measurements, device titration, and follow-up sleep studies.

STUDY DESIGN

Expert panel development of best Practice algorithm.

SETTING

Multi-institutional investigator review.

METHODS

An expert panel was assembled of pediatric otolaryngologists with extensive experience in hypoglossal nerve stimulation in children with Down Syndrome. Thirty statements were created during an initial drafting session. A modified Delphi method was used assess consensus among the panel.

RESULTS

After 2 rounds of Delphi surveys, 29 statements met criteria for consensus. One statement did not meet consensus. The statements were grouped into several categories to facilitate presentation.

CONCLUSIONS

A standardized approach to UAS for children with Down Syndrome must take into account the unique challenges inherent to treating a complex pediatric population with a high rate of sensory processing disorders. This expert panel has met consensus on several statements that will guide clinicians as this novel therapy is adopted.

Relationship of Nocturnal Insomnia Symptoms and Outcomes After Hypoglossal Nerve Stimulation

Objective

In patients undergoing hypoglossal nerve stimulation (HGNS), we examined the Insomnia Severity Index (ISI) to understand how baseline sleep onset insomnia (SOI), sleep maintenance insomnia (SMI), and early morning awakening (EMA) affected postsurgical outcomes.

Study Design

Observational.

Setting

Multicenter registry.

Methods

We included patients from the Adherence and Outcomes of Upper Airway Stimulation for Obstructive Sleep Apnea International Registry (ADHERE) with a baseline ISI from 2020 to 2023. Regression analysis examined the association of ISI question scores for SOI, SMI, and EMA and outcomes: Apnea-Hypopnea Index (AHI) reduction, device usage, changes in the Epworth Sleepiness Scale (ESS) and overall ISI score, final visit (FV) completion, and satisfaction.

Results

No relationship was noted between insomnia subtypes and AHI reduction or FV completion. In the subgroup of patients with baseline moderate/severe insomnia, patients with major impairment for SOI used their device 64 min/day longer than those with minimal impairment. Among all patients, those with baseline major impairment for SOI had a 2.3 points greater improvement in ISI from baseline to FV compared to patients with minimal impairment, while patients with baseline major impairment for SMI had a 2.0 and 3.5 points greater improvement in the ESS and ISI than those with minimal impairment. Patients with EMA and moderate/severe baseline insomnia had decreased odds of being satisfied after surgery.

Conclusion

In ADHERE, nocturnal symptoms of insomnia did not limit HGNS efficacy or therapy use. Conversely, those with worse insomnia subtype impairments at baseline had improved outcomes related to adherence, sleepiness, and insomnia at the FV.

Case report of hypoglossal nerve stimulation therapy failure due to significant underlying central sleep apnea

Hypoglossal nerve stimulation (HNS) is indicated for obstructive sleep apnea (OSA) but is ineffective in treating central sleep apnea (CSA). We describe two patients implanted with HNS after being diagnosed with OSA at outside sleep labs and failing a trial of continuous positive airway pressure (CPAP) therapy. Despite successful HNS implantation, the patients continued to have persistent symptoms with residual apnea-hypopnea indices above 25 events/h. Although OSA was the presenting diagnosis, we discovered a significant CSA component in the original diagnostic sleep data upon careful review. One patient was confirmed to have a CSA-predominant sleep disorder and improved with adaptive servo ventilation therapy. The other was diagnosed with central sleep apnea and severe periodic limb movement disorder, and improved with medication. Based on these sleep apnea cases, we propose guidelines emphasizing the importance of reviewing basic clinical information upon treatment failure and initiating multi-disciplinary collaboration early in the treatment course.

Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters

STUDY OBJECTIVES

Hypoglossal nerve stimulation is an established therapy for sleep apnea syndrome. Whether or not this therapy on snoring and nighttime noise exposure is effective and how strong this effect may be has not been objectively investigated thus far and was the aim of this study.

METHODS

In 15 participants (14 males; age: 30-72 years; mean: 51.7 years), polysomnography and acoustic measurements were performed before and after hypoglossal nerve stimulation.

RESULTS

The therapy led to a significant improvement in sleep apnea (apnea-hypopnea index from 35.8 events/h to 11.2 events/h, P < .001). Acoustic parameters showed a highly significant reduction in the average sound pressure level (42.9 db[A] to 36.4 db[A], P < .001), averaged sound energy, A-weighted (LAeq; 33.1 db[A] to 28.7 db[A], P < .001), snoring index (1,068 to 506, P < .001), percentage snoring time (29.7-14.1%, P < .001), and psychoacoustic snore score, the latter being a measure of annoyance due to snoring (47.9 to 24.5, P < .001).

CONCLUSIONS

This study was able to show for the first time by means of objective acoustic and psychoacoustic parameters that hypoglossal nerve stimulation can not only cause a significant improvement in sleep apnea but also has a positive effect on snoring and thus noise annoyance experienced by the bed partner.

CLINICAL TRIAL REGISTRATION

Registry: German Clinical Trials Register; Name: Effect of Hypoglossal Nerve Stimulation on Snoring: An Evaluation Using Objective Acoustic Parameters; URL: https://drks.de/search/de/trial/DRKS00032354; Identifier: DRKS00032354.

CITATION

Fischer R, Vielsmeier V, Kuehnel TS, et al. Effect of hypoglossal nerve stimulation on snoring: an evaluation using objective acoustic parameters. J Clin Sleep Med. 2024;20(3):363-370.

Mitigating Infection Risk in Upper Airway Stimulation

OBJECTIVE

This study aims to define the incidence of infection with upper airway stimulation (UAS) devices requiring explantation in a single academic center and identify factors that may influence the risk of infection.

METHODS

A database of patients who underwent UAS at a single tertiary referral academic center from 2017 to 2021 was retrospectively reviewed to identify patients who developed surgical site infections, with and without subsequent explantation. Additional data for cases complicated by infection was extracted from the electronic medical record (EMR) and included: demographic information, medical history, complications and management, and overall outcomes. In March 2021, 2 modifications to infection control protocols were implemented: double skin preparation with Betadine and chlorhexidine, and MRSA decolonization. Statistical analysis was performed to compare infectious risk before and after these protocol changes.

RESULTS

In the study period, 215 patients underwent UAS in the specified time period and 3 cases (1.4%) of postoperative infections were identified, all of which required explantation. The infection rate did not significantly change after modifications to the surgical prep protocol (P = .52).

CONCLUSIONS

While no significant difference in infection risk was noted after modifying infection control protocols, additional longer-term study is warranted to elucidate effective infection reduction strategies.

Hypoglossal nerve stimulation over-titration

This case report reviews worsening obstructive sleep apnea (OSA) events in a patient over-titrated with a hypoglossal nerve stimulator (HNS). A healthy 57-year-old man underwent HNS implantation for moderate OSA. During an in- laboratory HNS titration the patient had improvement of his OSA at 2.1V. However further increase of voltage resulted in worsening of obstructive events. The pathophysiology behind this finding is unknown but may result from unfavorable changes in the upper anatomy due to higher energy delivered to the hypoglossal nerve and surrounding structures. This high energy may also lead to genioglossus muscle fatigue. This finding highlights the importance of hypoglossal nerve stimulation titration with a dedicated sleep study.

Palate shape is associated with Unilateral Hypoglossal Nerve Stimulation Outcomes

OBJECTIVE

The aim was to determine the potential association between palate shape and unilateral hypoglossal nerve stimulation (HNS) outcomes.

METHODS

Preoperative drug-induced sleep endoscopy (DISE) videos were reviewed and scored by 3 blinded reviewers to determine airway narrowing at the hard-soft palate junction (HP), soft palate genu, and inferior velum, as described by Woodson (2014). Scoring was as follows: 1-open airway, 2-narrow, 3-severe narrowing. Overall palate shape (oblique, intermediate, or vertical) was determined based on prior criteria. Successful surgical treatment was defined by the HNS titration polysomnogram as a reduction of ≥50% in the apnea-hypopnea index (AHI) to <15 events/h.

RESULTS

Of 332 adults, the majority was male (77%) with an average BMI of 29.2 ± 3.6 kg/m2 . Overall success rate was 73%. Success rate was lower in patients with vertical palate shape compared with the other shapes (56% vs. 75%, p = 0.029). HP score 3 compared with scores 2 and 1 was associated with lower success rates (60% vs. 76%, p = 0.028), but genu and velum scores were not associated with outcomes. Patients with both HP score 3 and complete oropharyngeal lateral wall-related obstruction had notably worse outcomes (22% vs. 74%, p = 0.026). HP score 3 (OR 0.45, 95%CI 0.22-0.92) and vertical palate shape (OR 0.33, 95%CI 0.15-0.78) were independently associated with lower odds of surgical response after adjustment for DISE findings, age, gender, and BMI.

CONCLUSION

Vertical palate shape and narrowing at the hard-soft palate junction are independently associated with lower HNS surgical success rates.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:981-986, 2024.

Clinical Characteristics of Older Adults Seeking Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

OBJECTIVES

Obstructive sleep apnea (OSA) is a common sleep disorder with numerous clinical correlates. Although effective treatments abound, patient acceptance and adherence is low. Hypoglossal nerve stimulation (HNS) is a surgical treatment alternative for the treatment of OSA; however, the demographic and clinical characteristics of individuals seeking HNS are not well categorized. This study sought to determine the clinical characteristics of older adults seeking HNS for the treatment of OSA.

METHODS

Self-report questionnaires were administered to all patients older than 50 years seeking a HNS consultation at a large university medical center. Questionnaires included validated National Institutes of Health Patient-Reported Outcomes Measurement Information System (NIH PROMIS) measures of physical functioning, sleep-related impairment, cognitive abilities, depression, anxiety, and anger along with the Information extracted from electronic medical records included age, sex, race, and apnea-hypopnea index (AHI).

RESULTS

Patients included 113 adults (mean age 63.30 years, 57% male, 79% white) with severe OSA (AHI = 33.91, standard deviation = 20.63). Overall, 88% of patients reported elevated insomnia symptoms, 30% reported mild difficulty with physical functioning, and 36% indicated that they had experienced moderate-severe daytime impairments attributed to poor sleep. Additionally, we found 28% of sampled individuals reported moderate-severe depressive symptomology, over 19% reported moderate-severe anxiety, and over 17% reported moderate to severe anger issues. Approximately, 38% of the sample reported moderate to severe cognitive difficulties.

CONCLUSIONS

The aim of the study was to better understand the clinical characteristics of older patients with OSA seeking HNS treatment. Utilizing NIH PROMIS questionnaires, we identified unique clinical and psychosocial correlates in this sample, which included higher rates of insomnia symptoms, physical dysfunction, cognitive deficits, and depressive symptoms than the general population. Future studies will be needed to investigate these relationships more thoroughly and throughout the course of the treatment.

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.

Impact of Insomnia on Hypoglossal Nerve Stimulation Outcomes in the ADHERE Registry

OBJECTIVE

We aimed to determine the preoperative prevalence of insomnia in the Adherence and Outcomes of Upper Airway Stimulation for OSA International Registry (ADHERE) and to examine serial sleep-related data longitudinally, in particular the Insomnia Severity Index (ISI), to compare outcomes between patients with no/subthreshold insomnia (ISI < 15) and moderate/severe insomnia (ISI ≥ 15) at baseline.

METHODS

We analyzed observational data from ADHERE between March 2020 and September 2022. Baseline demographic and mental health (MH) data, apnea hypopnea index (AHI), ISI, and ESS (Epworth Sleepiness Scale) were recorded. At post-titration (PT) and final visits, AHI, ISI, ESS and nightly usage were compared between baseline ISI < 15 and ISI ≥ 15 subgroups.

RESULTS

A baseline ISI was obtained in 928 patients (62% with ISI ≥ 15). Of the 578 and 141 patients reaching the 12- and 24-month time periods to complete PT and final visits, 292 (50.5%) and 91 (64.5%) completed the ISI, respectively. Baseline MH conditions were higher with ISI ≥ 15 than ISI < 15 (p < 0.001). AHI reduction and adherence did not differ between patients with baseline ISI ≥ 15 and ISI < 15. Patients with ISI ≥ 15 experienced greater improvement in ESS than ISI < 15 at post-titration and final visits (p = 0.014, 0.025). All patients had improved nocturnal, daytime, and overall ISI scores at follow-up visits (p < 0.001), especially for those with baseline ISI ≥ 15 compared with ISI < 15 (p < 0.05).

CONCLUSION

HGNS therapy efficacy and adherence were similar between ISI severity subgroups at follow-up visits. Insomnia and sleepiness scores improved in all patients with HGNS therapy and to a greater degree in patients with baseline moderate/severe insomnia.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:471-479, 2024.

Comparison of clinical pathways for hypoglossal nerve stimulation management: in-laboratory titration polysomnography vs home-based efficacy sleep testing

STUDY OBJECTIVES

We conducted this study to evaluate whether laboratory or home-based hypoglossal nerve stimulation (HNS) management would have equivalent objective and subjective obstructive sleep apnea outcomes 6 months after activation.

METHODS

Patients undergoing standard-of-care HNS implantation were randomly assigned in a prospective, multicenter clinical trial to either a 3-month postactivation in-laboratory titration polysomnography (tPSG) or an efficacy home sleep study (eHST) with tPSG by exception for eHST nonresponders at 5 months. Both groups underwent an eHST 6 months postactivation.

RESULTS

Sixty patients were randomly assigned. Patients experienced equivalent decreases in the apnea-hypopnea index (mean difference: -0.01 events/h [-8.75, 8.74]) across both groups with HNS; the selection of tPSG or eHST did not associate with therapy response rates (tPSG vs eHST: 63.2% vs 59.1%). The Epworth Sleepiness Scale (median of differences: 1 [-1, 3]) and device usage (median of differences: 0.0 hours [-1.3, 1.3]) outcomes were similar but did not meet a priori statistical equivalence criteria.

CONCLUSIONS

This prospective, multicenter, randomized clinical trial demonstrated that patients undergoing HNS implantation experienced statistically equivalent improvements in objective obstructive sleep apnea outcomes and similar improvements in daytime sleepiness regardless of whether they underwent tPSG. HNS titration with tPSG may not be required for all postoperative patients.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Inspire Home Study: Utilization of Home Monitoring During Therapy Optimization in Patients With an Inspire Upper Airway Stimulation System (Comparison of Home Sleep Testing vs. In-lab Polysomnography Testing) (HOME); URL: https://clinicaltrials.gov/ct2/show/NCT04416542; Identifier: NCT04416542.

CITATION

Kent D, Huyett P, Yu P, et al. Comparison of clinical pathways for hypoglossal nerve stimulation management: in-laboratory titration polysomnography vs home-based efficacy sleep testing. J Clin Sleep Med. 2023;19(11):1905-1912.

Case report: An OSAS patient with comorbid RLS/PLMS - a closer look at the causes of PAP intolerance

Since 2017, hypoglossal nerve stimulation has been included in the S3-guidelines on restorative sleep/sleep disorders as an alternative treatment for patients with obstructive sleep related breathing disorders who cannot tolerate conventional PAP-therapy. Under certain conditions, some of these patients have the option to have a tongue pacemaker implanted during a surgical procedure to regain a restful night's sleep. However, in some cases it does not solve the problem. In this case report, we present a patient who continued to have restless sleep despite implantation of a hypoglossus nerve stimulator. We provide a closer look at the underlying causes of PAP intolerance and emphasize the importance of a combined pneumological and neurological approach to sleep medicine in sleep-specific therapy evaluation.

Successful Reimplantation of Extruded Lead after Hypoglossal Nerve Stimulation Surgery

Infection and extrusion of hardware are known complications of hypoglossal nerve stimulation surgery. We present a unique case of an extruded hardware lead successfully managed with reimplantation without need for explantation and new device placement. The topic will be discussed in context of the body of literature related to extruded medical device management. Laryngoscope, 133:2821-2822, 2023.

Long-Term Generator Replacement Experience in Hypoglossal Nerve Stimulator Therapy Recipients With CPAP-Intolerant Obstructive Sleep Apnea

OBJECTIVE

In the last decade, hypoglossal nerve stimulation (HNS) has emerged as a therapeutic alternative for patients with obstructive sleep apnea. The original clinical trial cohorts are entering the phase of expected battery depletion (8-12 years). This study aimed to examine the surgical experience with implantable pulse generator (IPG) replacements and the associated long-term therapy outcomes.

STUDY DESIGN

Retrospective analysis of patients from the original clinical trial databases (STAR, German post-market) who were followed in the ongoing ADHERE registry.

SETTING

International multicenter HNS registry.

METHODS

The ADHERE registry and clinical trial databases were cross-referenced to identify the serial numbers of IPGs that were replaced. Data collection included demographics, apnea-hypopnea index (AHI), therapy use, operative times, and adverse events.

RESULTS

Fourteen patients underwent IPG replacement 8.3 ± 1.1 years after their initial implantation. Body mass index was unchanged between the original implant and IPG replacement (29 ± 4 vs 28 ± 2 kg/m2 , p = .50). The mean IPG replacement operative time was shorter than the original implant (63 ± 50 vs 154 ± 58 minutes, p < .002); however, 2 patients required stimulation lead replacement which significantly increased operative time. For patients with available AHI and adherence data, the mean change in AHI from baseline to latest follow-up (8.7 ± 1.1 years after de novo implant) was -50.06%, and the mean therapy use was 7.2 hours/night.

CONCLUSION

IPG replacement surgery was associated with low complications and shorter operative time. For patients with available outcomes data, adherence and efficacy remained stable after 9 years of follow-up.

Hypoglossal Nerve Stimulation as Treatment for Obstructive Apnea in a Patient with a Pharyngeal Flap

Hypoglossal nerve stimulation can be a successful form of treatment for obstructive sleep apnea in patients with a pharyngeal flap. Although the Inspire device is geared at relieving obstructive sleep apnea due to tongue base obstruction, it can still be highly efficacious in improving AHI and OSA symptoms in the presence of nasopharyngeal narrowing from the pharyngeal flap. Laryngoscope, 133:2428–2429, 2023

Upper Airway Stimulation in Female Patients: Safety and Efficacy of a Novel Lateral Approach

OBJECTIVE

To describe a novel lateral approach for hypoglossal nerve stimulator (HNS) implantation in women and provide evidence for its safety and efficacy.

STUDY DESIGN

Retrospective case series.

SETTING

Single academic medical center.

METHODS

We identified patients implanted with HNS by a single surgeon from January 2017 to December 2021. Patient characteristics, postoperative complications, surgical duration, response to therapy, and need for revision surgery were recorded.

RESULTS

One hundred four patients were included, including 93 males and 11 females. The lateral approach for HNS implantation involves placing the chest incision for the implantable pulse generator and respiratory sensor lead vertically in the anterior axillary line instead of horizontally in the infraclavicular area. No changes are made to the stimulator lead placement. All female patients were implanted using a lateral approach and all male patients were implanted via the standard anterior approach. Half of the patients were implanted via a 2-incision technique. The median surgical time duration was equivalent in male and female patients (119 [interquartile range (IQR): 105-138] vs 126 [IQR: 115-141], respectively). Revision was required in 2 (18%) females versus 6 (6%) males (p = .17). There were equivalent rates of therapy response as well as postoperative complications.

CONCLUSION

A more cosmetic lateral approach is feasible for HNS in female patients and has a similar rate of adverse events and therapy responsiveness. Additional considerations in female patients include the ability to tolerate mammography as well as HNS implantation in the setting of existing breast implants.

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.

Longitudinal Effects of Base of Tongue Concurrent Chemoradiation Therapy in a Pre-Clinical Model

BACKGROUND/OBJECTIVES

Base of tongue (BOT) dysfunction is common following oropharyngeal concurrent chemoradiation therapy (CCRT). We present a clinically relevant animal model quantifying the effects of CCRT on tongue strength and elasticity over time.

METHODS

Fifty-three male and 53 female Sprague-Dawley rats were randomized to control or experimental groups. Experimental animals received cisplatin, 5-fluorouracil, and 5 fractions of 7 Gy directed to the BOT. Controls received no intervention. At 2 weeks, 5 months, or 10 months after CCRT, animals underwent non-survival surgery to measure twitch and tetanic tongue strength, which were analyzed using multivariate linear mixed effects models. Tongue displacement, a surrogate for tongue elasticity, was also determined via stress-strain testing and analyzed via a multivariate linear mixed effects model.

RESULTS

Reporting the combined results of both sexes, the estimated experimental group mean peak twitch forces became more divergent over time compared to controls, being 8.3% lower than controls at 2 weeks post-CCRT, 15.7% lower at 5 months, and 31.6% lower at 10 months. Estimated experimental group mean peak tetanic forces followed a similar course and were 2.9% lower than controls at 2 weeks post CCRT, 20.7% lower at 5 months, and 27.0% lower at 10 months. Stress-strain testing did not find CCRT to have a significant effect on tongue displacement across experimental timepoints.

CONCLUSIONS

This study demonstrates an increasing difference in tongue strength over time between controls and animals exposed to CCRT. Tongue elasticity was not significantly affected by CCRT, suggesting that changes in strength may not be caused by fibrosis.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:1455-1461, 2023.

Changes in tongue morphology predict responses in pharyngeal patency to selective hypoglossal nerve stimulation

STUDY OBJECTIVES

The major goal of the study was to determine whether changes in tongue morphology under selective hypoglossal nerve therapy for obstructive sleep apnea were associated with alterations in airway patency during sleep when specific portions of the hypoglossal nerve were stimulated.

METHODS

This case series was conducted at the Johns Hopkins Sleep Disorders Center at Johns Hopkins Bayview Medical Center. Twelve patients with apnea implanted with a multichannel targeted hypoglossal nerve-stimulating system underwent midsagittal ultrasound tongue imaging during wakefulness. Changes in tongue shape were characterized by measuring the vertical height and polar dimensions between tongue surface and genioglossi origin in the mandible. Changes in patency were characterized by comparing airflow responses between stimulated and adjacent unstimulated breaths during non-rapid eye movement sleep.

RESULTS

Two distinct morphologic responses were observed. Anterior tongue base and hyoid-bone movement (5.4 [0.4] to 4.1 [1.0] cm (median and [interquartile range]) with concomitant increases in tongue height (5.0 [0.9] to 5.6 [0.7] cm) were associated with decreases in airflow during stimulation. In contrast, comparable anterior hyoid movement (tongue protrusion from 5.8 [0.5] to 4.5 [0.9] cm) without significant increases in height (5.2 [1.6] to 4.6 [0.8] cm) were associated with marked increases in airflow during sleep.

CONCLUSIONS

Tongue protrusion with preservation of tongue shape predicted increases in patency, whereas anterior movement with concomitant increases in height were associated with decreased pharyngeal patency. These findings suggest that pharyngeal patency can be best stabilized by stimulating lingual muscles that maintain tongue shape while protruding the tongue, thereby preventing it from prolapsing posteriorly during sleep.

CITATION

Fleury Curado T, Pham L, Otvos T, et al. Changes in tongue morphology predict responses in pharyngeal patency to selective hypoglossal nerve stimulation. J Clin Sleep Med. 2023;19(5):947-955.

Total Intravenous Anesthesia Versus Inhaled Sevoflurane in Obstructive Sleep Apnea Surgery: A Randomized Controlled Trial

OBJECTIVE

Specific guidelines regarding an optimal general anesthesia (GA) approach to obstructive sleep apnea (OSA) patients remain undefined. Literature comparing the efficacy of total intravenous anesthesia (TIVA) and inhalational anesthesia in this population is sparse. We hypothesize that OSA patients receiving TIVA will experience reduced recovery times and other improved post-surgical outcomes.

STUDY DESIGN

Randomized controlled trial.

METHODS

Adult OSA patients undergoing upper airway surgery (hypoglossal nerve stimulation [HNS], nasal, or palate surgery) from February 2020-December 2020 were included. A post-anesthesia care unit (PACU) nursing survey documented patients' alertness, pain, oxygen supplementation, and postoperative nausea and vomiting from PACU arrival to 2 hours. Perioperative timepoints from the electronic medical record (EMR) and a nurse-estimated Phase I recovery time were collected.

RESULTS

One hundred eleven patients were included (46 TIVA and 65 inhalational anesthesia). Per EMR-recorded timepoints, TIVA patients undergoing HNS and palate surgery experienced Phase I Time reductions of 12.5 min (p = 0.042) and 27.5 min (p = 0.016), respectively. Per the PACU survey, TIVA patients undergoing any surgery, HNS, or palate surgery experienced nurse-estimated Phase I Time reductions of 16.5 min (p = 0.004), 12.5 min (p = 0.031), and 38.5 min (p = 0.024), respectively. Overall, TIVA patients experienced higher alertness and pain ratings, and lower oxygen supplementation requirements from PACU arrival to 30 min (p < 0.05).

CONCLUSION

Patients with OSA receiving TIVA for GA maintenance during upper airway procedures experienced reduced recovery times and oxygen supplementation requirements, and a more rapid return to alertness. Future work toward developing optimized anesthetic guidelines for OSA patients is merited.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:984-992, 2023.

Iatrogenic Pneumothorax During Hypoglossal Nerve Stimulator Implantation: A Large Database Analysis

OBJECTIVE

There have been case reports of adverse events of hypoglossal nerve stimulator (HNS) implantation not seen in previous clinical trials, including pneumothorax and pleural effusion. The purpose of this study was to determine the rates of these complications and potential risk factors.

STUDY DESIGN

Retrospective case-control study during 2014 to 2021.

SETTING

Twenty-five health care organizations across the United States.

METHODS

The TriNetX Research Network was queried by using disease codes to retrospectively identify patients with obstructive sleep apnea who underwent HNS implantation. Rates of pneumothorax, pleural effusion, other complications, and need for revision/replacement or explant were determined.

RESULTS

We identified 1813 patients from 25 health care organizations who underwent HNS implantation. The average age was 60 years, and there were 68% males and 32% females. Of the cohort, 2.4% (n = 44 from 7 implant centers) experienced a pneumothorax, and 0.6% (n = 11) were diagnosed with a pleural effusion on the day of surgery. Patients who experienced pneumothorax were more likely to have a history of chronic lower respiratory diseases when compared with those who did not (odds ratio, 2.2; 95% CI, 1.1-4.1; P = .02).

CONCLUSION

The incidence of intraoperative pneumothorax and pleural effusion during HNS implantation may be greater than initially thought. Patients with chronic lower respiratory diseases may be at increased risk. This should be communicated with patients during the informed consent process.

Treatment of obstructive sleep apnea with hypoglossal nerve stimulation in a patient with Ehlers-Danlos syndrome

Ehlers-Danlos syndrome is a group of hereditary connective tissue disorders caused by defects in collagen synthesis and structure that manifests as tissue fragility, hypermobility, and vascular abnormalities. Patients with Ehlers-Danlos syndrome are at a high risk of developing obstructive sleep apnea due to increased tissue laxity in the upper airway, in addition to nasal-maxillary cartilaginous defects, scoliosis, or other abnormalities. Here we present the case of a patient with Ehlers-Danlos syndrome who underwent successful treatment of obstructive sleep apnea using hypoglossal nerve stimulation after continuous positive airway pressure therapy failure, demonstrating that this can be a useful treatment modality in this population.

CITATION

Miller SM, Miller MB. Treatment of obstructive sleep apnea with hypoglossal nerve stimulation in a patient with Ehlers-Danlos syndrome. J Clin Sleep Med. 2023;19(3):631-632.

Electric field aspects in hypoglossal nerve stimulation for obstructive sleep apnea: A bilateral electrophysiological evaluation of unilateral electrode configuration changes

Hypoglossal nerve stimulation is an established treatment option for obstructive sleep apnea in selected patients. A unilateral hypoglossal nerve stimulation system was approved a decade ago, yet the physiological effect of unilateral hypoglossal stimulation on bilateral tongue motion remains unclear. This study examined how electrode configuration, stimulation cuff position, or body mass index influenced the contralateral genioglossus electromyography (EMG) signal. Twenty-nine patients underwent three EMG recordings in a polysomnographic setting after being implanted with a unilateral hypoglossal nerve stimulator for at least 6 months. The ratio of EMG signals between the ipsi- and contralateral sides was evaluated. No difference in EMG signals was demonstrated based on electrode configurations, stimulation-cuff position, body-mass-index, or sleep apnea severity, even in patients with right tongue protrusion only. Our findings may be explained by a significant level of cross-innervation and by a smaller and less variable circumferential electric field than expected based on prior biophysical models. A patient's individual anatomy needs to be considered during therapy titration in order to achieve an optimal response.

Palatal Coupling Maneuvers Do Not Predict Hypoglossal Nerve Stimulator Treatment Efficacy

OBJECTIVE(S)

Maneuvers during drug-induced sleep endoscopy (DISE), for patients with obstructive sleep apnea (OSA), have been used as predictors for success with oral appliances. Hypoglossal nerve stimulation (HGNS) promotes opening at the velum through palatoglossus coupling. In this study, we evaluate maneuvers during DISE as predictors for HGNS treatment efficacy.

METHODS

We evaluated patients undergoing HGNS between November, 2014 and February, 2021. We assessed maneuvers including jaw thrust and chin lift during preoperative DISE. The impact of tongue base and palatal opening during these maneuvers were rated from 1 to 4 (1: no improvement, 2: mild improvement, 3: moderate improvement, 4: significant improvement). Patients were grouped by a score of 1-2 (weak response) or 3-4 (strong response). Apnea hypopnea index (AHI) change was calculated from the difference between preoperative and postoperative sleep study.

RESULTS

One hundred and seventy one patients were included. With jaw thrust, there was no significant difference in AHI change between patients with weak or strong response at the palate (n = 68 vs. 94, 9.5 vs. 13.6, p = 0.21) or tongue base (n = 24 vs. 138, 16.6 vs. 11.3, p = 0.24). On chin lift, there was no significant difference at the palate (n = 82 vs. 18, 13.9 vs. 11.4, p = 0.63) or tongue base (n = 92 vs. 72, 10.8 vs. 14.6, p = 0.24). On multiple linear regression analysis, lower body mass index, higher preoperative AHI, and higher preoperative oxygen nadir were associated with a larger AHI change.

CONCLUSION

Palatal coupling maneuvers during DISE are not predictive of AHI change with HGNS. Findings using these maneuvers should not preclude HGNS candidacy.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:431-436, 2023.

Personalized multimodal management for severe obstructive sleep apnea in a patient intolerant of positive airway pressure with hypoglossal nerve stimulator and mandibular advancement device

Treatment of moderate to severe obstructive sleep apnea poses clinical challenges in persons with intolerance or inadequate response to traditional treatment modalities, including positive airway pressure and mandibular advancement devices. Hypoglossal nerve stimulation is a new treatment option, but few management guidelines exist when it is intolerable or ineffective. Combining several treatment modalities has been an effective strategy for improving symptoms, tolerance, and efficacy. We describe a patient intolerant to positive airway pressure therapy who had continued sleepiness, morning headaches, and snoring with a mandibular advancement device. He underwent hypoglossal nerve stimulation implantation but was intolerant of the voltages required to adequately control his obstructive sleep apnea. Multimodal management with hypoglossal nerve stimulation, mandibular advancement device, and positional therapy was successfully implemented to improve sleepiness, nocturnal symptoms, and the apnea-hypopnea index. This case highlights the personalization and adaptability of combination therapy to suit patient needs while effectively controlling obstructive sleep apnea.

CITATION

Lowery MM, Rundo JV, Walia HK, Shah V. Personalized multimodal management for severe obstructive sleep apnea in a patient intolerant of positive airway pressure with hypoglossal nerve stimulator and mandibular advancement device. J Clin Sleep Med. 2023;19(2):403-408.

Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report

We report the first case of bilateral hypoglossal nerve stimulator implantation in a patient with Treacher Collins syndrome and very severe obstructive sleep apnea, who was initially intolerant of continuous positive airway pressure (CPAP) treatment. Novel bilateral hypoglossal nerve stimulation in combination with CPAP allowed near obliteration of snoring, improved sleep quality, and ability to maintain the CPAP mask in position in the setting of craniofacial changes associated with this condition.

CITATION

Wong ACL, Jones A, Stone A, MacKay SG. Combination CPAP and bilateral hypoglossal nerve stimulation for obstructive sleep apnea in Treacher Collins syndrome: first case report. J Clin Sleep Med. 2023;19(1):197-199.

Disturbed Sleep is Not Good for the Heart: A Narrative Review

Sleep-related breathing disorders, including obstructive sleep apnea (OSA) and central sleep apnea (CSA), have a major impact on cardiovascular function. It has shown an association with hypertension, coronary artery disease, cardiac arrhythmias, sudden cardiac death, and congestive heart failure (CHF). This review focuses on highlighting the relationship between sleep apnea and CHF. We discuss the underlying pathophysiology, which involves the mechanical, neurohormonal, and inflammatory mechanisms; in addition, the similarities and differentiating clinical features of OSA in patients with CHF and without CHF. We have also discussed several treatment strategies, including weight loss, continuous positive airway pressure (CPAP), supplemental oxygen therapy, theophylline, acetazolamide, mandibular advancement device, and hypoglossal nerve stimulation (HGNS). We conclude that since there are several overlapping clinical features in patients with OSA with Heart Failure (HF) and without HF, early detection and treatment are crucial to decrease the risk of HF, coronary artery disease, and stroke.

Supine Pharyngeal Width Is Associated With Complete Concentric Palatal Collapse During Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulator Outcomes

OBJECTIVE

Hypoglossal nerve stimulation (HNS) implantation in the US requires preoperative drug-induced sleep endoscopy (DISE) screening for complete concentric palatal collapse (CCC) to establish treatment candidacy. We hypothesized that supine pharyngeal width (SPW) in awake patients is associated with CCC and HNS therapy outcomes.

METHODS

Adults with moderate to severe obstructive sleep apnea underwent awake measurement of SPW followed by DISE screening for CCC. Eligible patients electing for HNS implantation underwent postoperative polysomnography per standard of care.

RESULTS

SPW was measured in 73 patients. For SPW >20 mm, the positive likelihood ratio for absence of CCC was 6.67 with pre- and post-test odds of 6.3 and 42.0, respectively. Postoperative PSG data were available from 31 of 44 (70.5%) patients subsequently implanted with HNS. Patients with SPW >20 mm had a greater rate of HNS response than those with SPW ≤20 (62 vs 30%; P < .05). Only SPW and BMI were significantly associated with CCC and HNS response in regression models.

CONCLUSION

In a retrospective cohort study, SPW was significantly associated with CCC and postoperative apnea-hypopnea index following HNS implantation. SPW may be a viable screening tool for HNS candidacy.

Short-Term Outcome of Unilateral Inspiration-Coupled Hypoglossal Nerve Stimulation in Patients with Obstructive Sleep Apnea

Hypoglossal nerve stimulation (HGNS) is a therapeutic option for patients with obstructive sleep apnea (OSA) and intolerance of positive airway pressure (PAP) therapy. Most reported data are based on multicentre pivotal trials with selected baseline core clinical features. Our aim was to investigate polysomnography (PSG)-based outcomes of HGNS-therapy in a patient cohort with higher average AHI and BMI than previously reported. Data of 29 consecutive patients (nine female; mean age: 55.52 ± 8.6 years, mean BMI 30.13 ± 3.93 kg/m²) were retrospectively evaluated. Numerical values of PSG- based metrics were compared before and after intervention using Wilcoxon's rank-sum test. AHI (38.57/h ± 12.71, 24.43/h ± 13.3, p < 0.001), hypopnea index (24.05/h ± 9.4, 15.27/h ± 8.23, p < 0.001), apnea index (14.5/h ± 12.05, 9.17/h ± 10.86, p < 0.01), snoring index (262.68/h ± 170.35, 143.48/h ± 162.79, p < 0.001), cortical arousal index (20.8/h ± 10.34 vs. 14.9/h ± 8.36, p < 0.01) and cumulative duration of apnea and hypopnea during sleep (79.79 min ± 40.32 vs. 48.62 min ± 30.56, p < 0.001) were significantly lower after HGNS. HGNS provides an effective therapy option for selected patients not tolerating PAP-therapy with higher average AHI and BMI than usually reported. HGNS-therapy appears to suppress central nervous system arousal circuits while not eliciting peripheral autonomous sympathetic activation. Such metrics as the snoring index and the cumulative duration of respiratory events during sleep may be considered in future HGNS studies.

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.

Does race-ethnicity affect upper airway stimulation adherence and treatment outcome of obstructive sleep apnea?

STUDY OBJECTIVES

Untreated obstructive sleep apnea (OSA) is associated with excessive daytime sleepiness, decreased quality of life, and cardiovascular disease. Positive airway pressure is the first-line therapy for OSA; however, adherence is difficult. Upper airway stimulation is a Food and Drug Administration-approved treatment of OSA. The objective of this study was to evaluate for a difference in treatment efficacy and adherence of upper airway stimulation therapy for OSA between individuals who are White and non-White using data from the ADHERE registry.

METHODS

ADHERE registry is a multicenter prospective study of real-world experience of upper airway stimulation for treatment of OSA in the United States and Europe. Propensity score matching was used to create a balanced dataset between the White and non-White groups. t-Tests at a significance level of 5% were used to compare numeric values between groups.

RESULTS

There were 2,755 participants of the ADHERE registry: 27 were excluded due to not having a race identified, 125 participants identified as non-White, 2,603 identify as White, and 27 did not provide race information. Propensity score matching was used to select 110 participants, with 55 White and 55 non-White for the noninferiority analysis. We did not find a difference in adherence, treatment apnea-hypopnea index, changes in Epworth Sleepiness Scale score, or clinical global impression after intervention score between White and non-White individuals.

CONCLUSIONS

Our study found that there was no statistically significant difference in adherence or efficacy with upper airway stimulation therapy between White and non-White individuals. However, the percent of non-White people implanted is low, which suggests a need to expand access to this therapy for non-White populations with OSA who cannot tolerate positive airway pressure therapy.

CITATION

Khan M, Stone A, Soose RJ, et al. Does race-ethnicity affect upper airway stimulation adherence and treatment outcome of obstructive sleep apnea? J Clin Sleep Med. 2022;18(9):2167-2172.

Home sleep apnea testing with peripheral arterial tonometry to assess outcome in upper airway stimulation

STUDY OBJECTIVES

To determine whether home sleep apnea testing with peripheral arterial tonometry (HSAT-PAT) can be used in upper airway stimulation to evaluate therapy success.

METHODS

Data analysis from 50 consecutive patients receiving upper airway stimulation was performed. Baseline values were measured by polysomnography and HSAT-PAT. Follow-up was performed during and after titration (3-6 months) by polysomnography and HSAT-PAT and after 1 year by HSAT-PAT only. Primary outcome measures were reduction in the apnea-hypopnea index and oxygen desaturation index. In addition, an analysis of night-to-night variability for HSAT-PAT was performed.

RESULTS

All 50 patients completed their posttitration visit (3-6 months) and 41 patients completed the 1-year follow-up. In HSAT-PAT after 1 year, the mean apnea-hypopnea index (desaturation 3%) was reduced from 29.5 ± 17.1 events/h to 19.9 ± 13.1 events/h (P < .01) and the oxygen desaturation index (desaturation 4%) was reduced from 17.8 ± 12.6 events/h to 10.2 ± 8.3 events/h (P < .01). Therapy adherence after 1 year was high (6.6 ± 1.9 hours per night) and led to improvement in daytime sleepiness, meaning a reduction in the Epworth Sleepiness Scale score from 12.8 ± 5.4 to 5.9 ± 4.0 (P < .01). Analysis of night-to-night variability showed similar apnea-hypopnea index values between the 2 nights.

CONCLUSIONS

Upper airway stimulation was able to reduce the apnea-hypopnea index and oxygen desaturation index after 1 year, as assessed by full-night efficacy studies with HSAT-PAT. In addition, improvements in self-reported outcome parameters were observed. The importance of publishing the scoring criteria is highlighted and whether data are based on full-night efficacy studies or a selected period of time from a sleep study. This is a prerequisite for comparing data with other trials in the emerging field of upper airway stimulation.

CITATION

Hinder D, Schams SC, Knaus C, Tschopp K. Home sleep apnea testing with peripheral arterial tonometry to assess outcome in upper airway stimulation. J Clin Sleep Med. 2022;18(9):2197-2205.

Clinical Predictors of OSA Treatment Success Following Implantation of a Hypoglossal Nerve Stimulation Device

OBJECTIVE

To identify prognostic indicators associated with successful hypoglossal nerve stimulation (HGNS) therapy to treat obstructive sleep apnea (OSA), focusing on patients' physiologic response to awake tongue protrusion.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care center.

METHODS

We included consecutive patients with moderate-severe OSA who underwent HGNS implantation from December 2017 to December 2019. Data abstracted include standard demographics, body mass index (BMI), pre- and postoperative apnea-hypopnea index (AHI), and Friedman tongue position (FTP). Additionally, change in hypopharyngeal cross-sectional area on awake tongue protrusion was abstracted. Patients protruded their tongues, and the physician visualized change. Positive change in hypopharyngeal cross-sectional area was documented as +1 and a negative change as -1. Chi-square tests for independence and logistic regression analysis were performed to determine indicators of successful surgery.

RESULTS

Thirty-nine patients were included in this study. Mean ± SD AHI decreased significantly from 43.1 ± 17.36 to 9.18 ± 8.18. Surgical success was achieved in 79.5% of patients. Variables analyzed included BMI >32, preoperative AHI, FTP, and change in hypopharyngeal cross-sectional area on awake tongue protrusion (positive, 65.8%; negative, 34.2%). Positive predictors of success were positive change in hypopharyngeal cross-sectional area (P = .0133), severe OSA (P = .0290), and FTP IIb (P < .0001). Negative predictors were BMI >32 (P = .041) and negative change in hypopharyngeal cross-sectional area (P = .02).

CONCLUSION

Positive change in hypopharyngeal cross-sectional area on awake tongue protrusion and severe baseline AHI were positive predictors of successful HGNS therapy. Negative change in hypopharyngeal cross-sectional area on awake tongue protrusion and BMI >32 were negative predictors.

Early objective adherence to hypoglossal nerve stimulation therapy

STUDY OBJECTIVES

To assess early adherence to therapy with hypoglossal nerve stimulation therapy.

METHODS

This is a prospective study of consecutive patients with moderate to severe obstructive sleep apnea who underwent implantation of hypoglossal nerve stimulation therapy within a single academic practice and attended a follow-up appointment after greater than 30 days of therapy use. Objective adherence data were extracted from an objective monitoring database and compared to patient characteristics.

RESULTS

The study population was 79 participants who were 29.1% female with a mean age of 58.7 ± 12.8 years old, body mass index of 28.9 ± 3.4 kg/m², and baseline apnea-hypopnea index of 33.8 ± 17.6 events/h. In the first 7 days after device activation, average use was 7.8 h/night, with 91.9% of nights with greater than 4 hours of therapy use and an average of 0.2 pauses in therapy per night. These figures remained stable after 30 days of use: 7.7 h/night, 91.0% of nights longer than 4 hours, and 0.3 pauses per night. Objective evidence of difficulty with acclimatization was associated with age less than 60 years (odds ratio 2.8, 95% confidence interval 1.1-7.1, P = .03) and a history of prior upper airway surgery (3.9, 1.2-11.9, P = .015). Insomnia was present in 31 patients and was not associated with objective evidence of difficulty tolerating therapy.

CONCLUSIONS

Early adherence to hypoglossal nerve stimulation is excellent (92.4% >4 hours on >70% of nights), suggesting that the acclimatization period is straightforward in most. Younger age and a history of prior upper airway surgery appear to be associated with an increased risk of difficulty with acclimatization.

CITATION

Huyett P. Early objective adherence to hypoglossal nerve stimulation therapy. J Clin Sleep Med. 2022;18(2):631-636.

Identifying Patient Characteristics That Predict Drug-Induced Sleep Endoscopy Anatomy

OBJECTIVE

To examine if age, sex, body mass index (BMI), neck circumference, or apnea-hypopnea index can predict whether a patient will demonstrate velopharyngeal complete circumferential (CC) collapse on drug-induced sleep endoscopy (DISE).

STUDY DESIGN

Single-center retrospective review at The Ohio State Wexner Medical Center of 289 patients between March 2014 and June 2020.

SETTING

Quaternary care hospital.

METHODS

Patient characteristic and DISE information was extracted from charts and summarized with mean and standard deviation for continuous variables and count and percentage for categorical. CC collapse and patient characteristic associations were explored: 2-sample t test for continuous and chi-square test for categorical. Classification and regression tree (CART) analysis with 3-fold cross-validation was employed to search for the best CC collapse predictors.

RESULTS

Male and female BMI and female neck circumference were correlated to velopharyngeal CC collapse, with BMI more strongly correlated. CART analysis for males showed that a BMI ≤34.8 kg/m² is associated with an 89.4% chance of not demonstrating velopharyngeal CC collapse vs 48% for BMI >34.8 (area under the curve [AUC] = 0.705; AUC >0.7 is acceptable). For females, the CART analysis showed that a BMI ≤36.4 is associated with a 98.4% of not demonstrating velopharyngeal CC collapse vs 30.8% for BMI >36.4 (AUC = 0.73). For females, a neck circumference ≤38.05 cm is associated with a 100% chance of not demonstrating velopharyngeal CC collapse vs 18.4% for >38.05 cm (AUC = 0.72).

CONCLUSION

The BMI values for males and females and the female neck circumference values established by the CART model may accurately predict DISE anatomy and possible candidacy for hypoglossal nerve stimulation.

Persistent Treatment-Emergent Central Sleep Apnea (TECSA) Following Hypoglossal Nerve Stimulation

PURPOSE

Since 2001, hypoglossal nerve stimulators (HNS) have been used worldwide to treat patients with obstructive sleep apnea (OSA). Recently, a few studies reported treatment-emergent central sleep apnea (TECSA) with spontaneous resolution following HNS. However, the evidence of persistent development of TECSA during long-term care visits was lacking. As a result, this study first report two patients with persistent TECSA and describe their development phenotype during more than two years of follow-up visits to help explore the influencing factors and underlying mechanisms.

PATIENTS AND METHODS

This retrospective study included twenty-seven patients who underwent HNS implantation from 2016 to 2021. Their demographic data, pre- and postoperative sleep study characteristics, and device use settings were collected. The possible factors associated with post-operative elevated CSA (central apnea index ≥5) were evaluated. Moreover, the development phenotype of the TECSA was observed and followed up with a titration trial study.

RESULTS

Among overall 27 patients with OSA, 3 patients with an increased preoperative Epworth Sleepiness Score (ESS) got an elevated CSA (CAI ≥ 5). Two of these 3 patients developed a persistent TECSA with a significant negative correlation between obstructive apnea index (OAI) and central and mixed sleep apnea index (CMAI) (R = -0.745, P = 0.021). These development phenotypes might be associated with different stimulation amplitudes of the HNS device. Furthermore, the following titration trial study also suggested that different amplitudes would influence the development of TECSA following HNS.

CONCLUSION

OSA patients with severe daytime sleepiness are more likely to have elevated CSA following HNS. An inappropriate stimulation amplitude might influence the development course of TECSA in such patients.

Neurophysiological profiles of responders and non-responders to hypoglossal nerve stimulation: a single institution study

STUDY OBJECTIVES

Hypoglossal nerve stimulation (HGNS) is an effective alternative treatment for obstructive sleep apnea (OSA) that acts by opening the airway via selective stimulation of nerve fibers that innervate tongue muscles that protrude (genioglossus) and stiffen the tongue (transverse and vertical) while avoiding nerve fibers that innervate tongue muscles that retract the tongue (styloglossus and hyoglossus). There remains a subset of post-operative patients who fail to adequately respond to HGNS, in some cases due to simultaneous mixed activation of muscles that protrude and retract the tongue. This study aims to characterize the relationship between neurophysiological data from individual tongue muscle activation during intraoperative electromyographic (EMG) recordings and post-operative AHI responses to HGNS..

METHODS

A single institution review of 46 patients undergoing unilateral HGNS implantation for OSA. Patients were separated into responders and non-responders through comparison of pre and postoperative AHI. Neurophysiological data included EMG responses of the genioglossus, styloglossus/hyoglossus, intrinsic/vertical, and hyoglossus (neck) muscles to intraoperative stimulation using unipolar (--- and o-o) and bipolar (+-+) settings.

RESULTS

The overall treatment success rate was 61% as determined by a post-operative AHI <20 events/hr with a greater than 50% AHI reduction. We observed no statistically significant relationships between treatment response and individual muscle responses. However, we did note that increasing BMI was correlated with worse post-operative responses.

CONCLUSIONS

Although we noted a significant sub-group of clinical non-responders to HGNS post-operatively, these patients were not found to exhibit significant inclusion of tongue retractors intraoperatively on neurophysiological analysis. Further research is needed to delineate additional phenotypic factors that may contribute to HGNS treatment responses.

Implantation of the hypoglossal nerve stimulator via left sided, 2-incision approach

This is a case series of 5 patients who underwent implantation of the hypoglossal nerve stimulator for obstructive sleep apnea via a left-sided, two incision technique. This represents a significant modification of the original right-sided, three-incision technique. All five patients were successfully implanted with this technique variant with no adverse events or negative impact on device functionality, such as cardiac artifact.

A Noninferiority Analysis of 3- vs 2-Incision Techniques for Hypoglossal Nerve Stimulator Implantation

OBJECTIVE

The only hypoglossal nerve stimulation (HNS) device available for US clinical use is implanted through 3 incisions. A recently proposed 2-incision modification moved the respiratory sensing lead from the fifth to the second intercostal space to eliminate the third lower chest incision. This study compared perioperative data and therapeutic outcomes between the techniques.

STUDY DESIGN

Noninferiority cohort analysis of a retrospective and prospective registry study.

SETTING

Tertiary care and community surgical centers.

METHODS

Patients with obstructive sleep apnea underwent HNS implantation via a modified 2-incision technique (I₂). A cohort previously implanted via the standard 3-incision technique (I₃) were 1:1 propensity score matched for a noninferiority analysis of postoperative outcomes.

RESULTS

There were 404 I₃ patients and 223 I₂ patients across 6 participating centers. Operative time decreased from 128.7 minutes (95% CI, 124.5-132.9) in I₃ patients to 86.6 minutes (95% CI, 83.7-97.6) in I₂ patients (P < .001). Postoperative sleep study data were available for 76 I₂ patients who were matched to I₃ patients. The change in apnea-hypopnea index between the cohorts was statistically noninferior (a priori noninferiority margin: 7.5 events/h; mean difference, 1.51 [97.5% CI upper bound, 5.86]). There were no significant differences between the cohorts for baseline characteristics, perioperative adverse event rates, or change in Epworth Sleepiness Score (P > .05).

CONCLUSION

In a multicenter registry, a 2-incision implant technique for a commercially available HNS device had a statistically noninferior therapeutic efficacy profile when compared with the standard 3-incision approach. The 2-incision technique is safe and effective for HNS implantation.

Post-operative Complication Rate Comparison Between Airway Surgery and Upper Airway Stimulation Using NSQIP and ADHERE

Objective

Postoperative complication rates were compared between obstructive sleep apnea surgery (OSAS) and hypoglossal nerve upper airway stimulation (UAS).

Study Design

Cohort.

Setting

Multi-institutional international databases.

Methods

OSAS data were collected from the NSQIP database (2014; American College of Surgeons National Surgery Quality Improvement Program). UAS data were obtained from the ADHERE registry (Adherence and Outcome of Upper Airway Stimulation for OSA International Registry; 2016-December 2019). ADHERE comorbidities and complications were categorized to match NSQIP definitions. A chi-square test was used for proportion P values.

Results

There were 1623 UAS procedures in ADHERE and 310 in NSQIP. The UAS group was older than the OSAS group (mean ± SD, 60 ± 11 vs 42 ± 13 years) but similarly male (75% vs 77%) and overweight (body mass index, 29 ± 4 vs 29 ± 3 kg/m²). There was a higher proportion of hypertension, diabetes, and heart disease in the UAS cohort. Palatopharyngoplasty was the most common surgical procedure (71%), followed by tonsillectomy (25%). UAS operative time was longer (132 ± 47 vs 54 ± 33 minutes). Postoperative length of stay was not normally distributed, as 71% of UAS stays were <1 day as opposed to 40% of OSA stays (P < .0001). Thirty-day return to the operating room related to the procedure was 0.1% for UAS and 4.8% for OSAS (P < .0001). Surgical site infections were 0.13% for UAS and 0.9% for OSAS (P = .046).

Conclusion

The UAS cohort was older and more likely to have comorbid hypertension, diabetes, and heart disease. Despite baseline differences, the postoperative complication rate was lower with UAS than with OSAS.

Hypoglossal Nerve Stimulation Usage by Therapy Nonresponders

OBJECTIVE

The purpose of this study is to examine differences in therapy usage and outcomes of therapy between responder (R) and nonresponder (NR) groups in an international, multicenter prospective registry of patients undergoing hypoglossal nerve stimulation for obstructive sleep apnea (OSA).

STUDY DESIGN

Database analysis (level III).

SETTING

International, multicenter registry.

METHODS

The studied registry prospectively collects data pre- and postimplantation, including sleep parameters, Epworth score, patient experience, and safety questions, over the course of 12 months. Patients are defined as a "responder" based on Sher criteria, which require a final apnea-hypopnea index (AHI) of ≤20 and a final AHI reduction of >50% at their 12-month follow-up.

RESULTS

Overall, there were 497 (69%) R and 220 (31%) NR. Most patients in both groups experienced improvement in quality of life following implantation (96% of R; 77% of NR) with reductions in oxygen desaturation index and Epworth score. At final follow-up, the R group demonstrated significantly better adherence to recommended therapy (>4 hours/night) (P = .001), average hours of nightly use (P = .001), final Epworth scores (P = .001), and degree of subjective improvement (P < .001).

CONCLUSION

Patients classified as NR to upper airway stimulation continue to use therapy with improvement in percent time of sleep with O₂ <90%, reduction in daytime sleepiness, and improvement in quality of life. Therefore, ongoing usage of the device should be encouraged in NR patients who note improvement while integrating additional strategies to lower the long-term effects of OSA.

Evaluating YouTube Videos on Hypoglossal Nerve Stimulation as a Resource for Patients

OBJECTIVES/HYPOTHESIS

This study evaluated the quality and comprehensiveness of YouTube videos on hypoglossal nerve stimulation (HNS) for patients. This study also investigated the relationship between video content, video metrics, and popularity.

STUDY DESIGN

Cross-sectional study.

METHODS

We identified 150 videos using three search terms: "inspire sleep apnea," "hypoglossal nerve stimulation," and "upper airway stimulation." Videos that were unrelated to the use of HNS for obstructive sleep apnea in adults, operating room recordings, lectures for medical professionals, non-English, or non-audio were excluded. Video quality and comprehensiveness were assessed using modified DISCERN criterion (range: 5-25) and novel content criterion (range: 0-12), respectively. Secondary outcomes included video metrics (views, likes, dislikes, comments, and days since upload) and Video Power Index to measure popularity. Outcomes were stratified by video uploader source (medical institutions, medical companies, individual users, other).

RESULTS

Users searched YouTube for "inspire sleep apnea" 2.48 times more in 2020 than in 2018. We identified 67 videos for review, with the majority coming from medical institutions (70.2%). Overall, the average-modified DISCERN (13.65 ± 4.88) and novel content (3.87 ± 2.09) scores were low and did not differ between medical institutions or other uploader sources. Higher quality and more comprehensive video content did not correlate with popularity.

CONCLUSION

Overall quality and comprehensiveness of information of HNS YouTube videos was low. Given the high demand for information on HNS, there is opportunity for medical institutions to implement new strategies to improve both video content and visibility to patients.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

INTRODUCTION

This systematic review provides supporting evidence for the accompanying clinical practice guideline on the referral of adults with obstructive sleep apnea (OSA) for surgical consultation.

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of upper airway sleep apnea surgery or bariatric surgery to no treatment as well as studies that reported on patient-important and physiologic outcomes pre- and postoperatively. Statistical analyses were performed to determine the clinical significance of using surgery to treat obstructive sleep apnea in adults. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 274 studies that provided data suitable for statistical analyses. The analyses demonstrated that surgery as a rescue therapy results in a clinically significant reduction in excessive sleepiness, snoring, blood pressure (BP), apnea-hypopnea index (AHI), respiratory disturbance index (RDI), oxygen desaturation index (ODI), increase in lowest oxygen saturation (LSAT), sleep quality, and improvement in quality of life in adults with OSA who are intolerant or unaccepting of positive airway pressure (PAP) therapy. The analyses demonstrated that surgery as an adjunctive therapy results in a clinically significant reduction in optimal PAP pressure and improvement in PAP adherence in adults with OSA who are intolerant or unaccepting of PAP due to side effects associated with high pressure requirements. The analyses also demonstrated that surgery as an initial treatment results in a clinically significant reduction in AHI/RDI, sleepiness, snoring, BP, and ODI, and increase in LSAT in adults with OSA and major anatomical obstruction. Analysis of bariatric surgery data showed a clinically significant reduction in BP, AHI/RDI, sleepiness, snoring, optimal PAP level, BMI, ODI, and an increase in LSAT in adults with OSA and obesity. Analyses of very limited evidence suggest that upper airway surgery does not result in a clinically significant increase in risk of serious persistent adverse events and suggested that bariatric surgery may result in a clinically significant risk of iron malabsorption that may be managed with iron supplements. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

Proceedings of the 2019 International Sleep Surgery Society Research Forum

Hypoglossal nerve stimulation (HGNS) has evolved as a novel and effective therapy for patients with moderate-to-severe obstructive sleep apnea (OSA). Despite positive published outcomes of HGNS, there exist uncertainties regarding proper patient selection, surgical technique, and the reporting of outcomes and individual factors that impact therapy effectiveness. According to current guidelines, this therapy is indicated for select patients, and recommendations are based on the Stimulation Therapy for Apnea Reduction (STAR) trial. Ongoing research and physician experiences continuously improve methods to optimize the therapy. An understanding of the way in which airway anatomy, OSA phenotypes, individual health status, psychological conditions and comorbid sleep disorders influence the effectiveness of HGNS is essential to improve outcomes and expand therapy indications. This manuscript presents discussions on current evidence, future directions, and research gaps for HGNS therapy from the 10th International Surgical Sleep Society expert research panel.

Impulse Configuration in Hypoglossal Nerve Stimulation in Obstructive Sleep Apnea: The Effect of Modifying Pulse Width and Frequency

OBJECTIVES

Hypoglossal nerve stimulation is an effective treatment option for obstructive sleep apnea (OSA) in positive airway pressure therapy failure. Nonetheless, data regarding the functional effect of modifying stimulation parameters within each electrode configuration are limited.

MATERIALS AND METHODS

In a retrospective study of 76 patients with 12 months or more follow-up, functional tongue protrusion thresholds were compared for pulse width and frequency configurations of 90 μsec 33 Hz vs 120 μsec 40 Hz. The number of tolerated voltage amplitude steps between sensation, functional, and subdiscomfort thresholds were assessed for both settings as well as impedances.

RESULTS

The overall cohort showed improvement in OSA metrics: median apnea-hypopnea index from 30.0/hour to 18.6/hour and Epworth Sleepiness Scale from 13.5 to 7.6. For both bipolar and unipolar electrode configurations, the stimulation amplitude required for functional tongue protrusion was significantly reduced when the pulse width and frequency were converted from 90 μsec 33 Hz to 120 μsec 40 Hz (p < 0.001). Nevertheless, the number of voltage amplitude steps from sensation, functional, to subdiscomfort thresholds did not differ between the two settings. The ratio of automatically derived impedances between bipolar and unipolar electrode configurations was relevantly correlated with the ratio of functional thresholds at these parameters.

CONCLUSION

Changing the stimulation parameters may lower the voltage requirements while maintaining the same effect on tongue protrusion. Changing these stimulation parameters does not affect the range of tolerated impulse steps between functional and subdiscomfort thresholds. Future technical appliances could help estimate functional thresholds at different electrode configurations for each patient by automatically measuring impedances.

Ansa cervicalis stimulation increases pharyngeal patency in patients with obstructive sleep apnea

Hypoglossal nerve stimulation (HNS) is an alternative treatment option for obstructive sleep apnea (OSA) that reduces pharyngeal collapsibility, but HNS nonresponders often demonstrate continued retropalatal and lateral pharyngeal wall collapse. Recent evidence suggests that caudal pharyngeal traction with sternothyroid muscle contraction via ansa cervicalis stimulation (ACS) can also stabilize the pharynx, but the underlying mechanisms have not been elucidated. Our objective was to evaluate the effect of ACS on pharyngeal patency during expiration when the airway is most hypotonic. Eight participants with OSA underwent sustained ultrasound-guided fine-wire stimulation of the medial branch of the right hypoglossal nerve with and without transient stimulation of the branch of the ansa cervicalis nerve plexus innervating the right sternothyroid muscle during drug-induced sleep endoscopy. Airway cross-sectional area and expiratory airflow (V̇e) were measured from endoscopy video with ImageJ and pneumotachometry, respectively. ACS significantly increased retropalatal cross-sectional area (CSA_RP) to 211% [159-263] of unstimulated CSA_RP (P < 0.05). Adding ACS to HNS increased CSA_RP from baseline by 341% [244-439] (P < 0.05), a 180% [133-227] increase over isolated HNS (P < 0.05). ACS increased V̇e from baseline by 177% [138-217] P < 0.05). Adding ACS to HNS increased V̇e by 254% [207-301], reflecting decreases in pharyngeal collapsibility. Combining ACS with HNS increased retropalatal cross-sectional area and increased expiratory airflow, suggesting decreases in pharyngeal collapsibility. Our findings suggest that ACS exerts caudal traction on the upper airway through sternothyroid muscle contraction and that it may augment HNS efficacy in patients with OSA.NEW & NOTEWORTHY Ansa cervicalis stimulation (ACS) is a recently proposed neurostimulation mechanism for generating caudal pharyngeal traction that may benefit patients with obstructive sleep apnea. Here, we document endoscopic findings with ACS during drug-induced sleep endoscopy and additionally detail the effects of ACS on expiratory airflow, when the pharynx is known to be most hypotonic.

Effect of Upper Airway Stimulation in Patients with Obstructive Sleep Apnea (EFFECT): A Randomized Controlled Crossover Trial

Background: Several single-arm prospective studies have demonstrated the safety and effectiveness of upper airway stimulation (UAS) for obstructive sleep apnea. There is limited evidence from randomized, controlled trials of the therapy benefit in terms of OSA burden and its symptoms. Methods: We conducted a multicenter, double-blinded, randomized, sham-controlled, crossover trial to examine the effect of therapeutic stimulation (Stim) versus sham stimulation (Sham) on the apnea-hypopnea index (AHI) and the Epworth Sleepiness Scale (ESS). We also examined the Functional Outcomes of Sleep Questionnaire (FOSQ) on sleep architecture. We analyzed crossover outcome measures after two weeks using repeated measures models controlling for treatment order. Results: The study randomized 89 participants 1:1 to Stim (45) versus Sham (44). After one week, the AHI response rate was 76.7% with Stim and 29.5% with Sham, a difference of 47.2% (95% CI: 24.4 to 64.9, p < 0.001) between the two groups. Similarly, ESS was 7.5 ± 4.9 with Stim and 12.0 ± 4.3 with Sham, with a significant difference of 4.6 (95% CI: 3.1 to 6.1) between the two groups. The crossover phase showed no carryover effect. Among 86 participants who completed both phases, the treatment difference between Stim vs. Sham for AHI was −15.5 (95% CI −18.3 to −12.8), for ESS it was −3.3 (95% CI −4.4 to −2.2), and for FOSQ it was 2.1 (95% CI 1.4 to 2.8). UAS effectively treated both REM and NREM sleep disordered breathing. Conclusions: In comparison with sham stimulation, therapeutic UAS reduced OSA severity, sleepiness symptoms, and improved quality of life among participants with moderate-to-severe OSA.

Relation between arousability and outcome of upper airway stimulation in the Stimulation for Apnea Reduction (STAR) Trial

STUDY OBJECTIVES

Upper airway stimulation (UAS) is an innovative surgical treatment for obstructive sleep apnea; however, the treatment failure rate is approximately 22%. Easy arousability may limit the tolerability of stimulation and, by extension, its effectiveness. The odds ratio product (ORP) is a continuous electroencephalographic metric of arousal propensity (range: 0 [deep sleep] to 2.5 [full wakefulness]), and its rate of decline after arousal (ORP-9) is a risk factor for susceptibility to arousal in the presence of frequent arousal stimuli. We hypothesized that individuals with deeper sleep (low average ORP and low ORP-9) are more likely to respond to UAS.

METHODS

ORP and ORP-9 were calculated from 126 baseline polysomnograms of participants in the STAR Trial. These values were compared between responders and nonresponders. Adjusted linear modeling was performed to determine the association between ORP-derived variables and treatment response.

RESULTS

No differences were found between responders and nonresponders in unadjusted comparisons of ORP-derived variables. On linear regression modeling, significant correlation was found between non-rapid eye movement ORP and reduction in apnea-hypopnea index (P = .004).

CONCLUSIONS

No significant difference in ORP was noted between responders and nonresponders to UAS therapy; however, contrary to our initial hypothesis, linear regression modeling trended toward a positive relationship between ORP and UAS response, suggesting that those who have lighter sleep are more likely to respond to therapy; however, these results are only exploratory, and future larger prospective studies are needed to confirm this relationship.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: STAR Trial; Identifier: NCT01161420.

Sleep Study Measures on Postoperative Night 1 Following Implantation of the Hypoglossal Nerve Stimulator

OBJECTIVE

To examine the changes in measures of sleep apnea severity and hypoxemia on the first postoperative night following implantation of the hypoglossal nerve stimulator.

STUDY DESIGN

This was a single-arm prospective cohort study.

SETTING

A single academic sleep surgical practice.

METHODS

Subjects with moderate to severe obstructive sleep apnea underwent implantation of the hypoglossal nerve stimulator (HGNS) and were discharged to home the same day as surgery. A single-night WatchPAT study was performed on the night immediately following surgery (PON 1) and was compared to baseline sleep testing.

RESULTS

Twenty subjects who were an average of 58.6 ± 2.5 years old, were 25% female, and had a mean body mass index of 28.1 ± 0.9 kg/m² completed the study. Mean O₂ nadir at baseline was 79.6% ± 1.1% compared to 82.7% ± 0.9% (P = .013) on PON 1. One patient demonstrated a >10% worsening in O₂ nadir. Only 2 additional patients demonstrated a worsening in O₂ nadir on PON 1, each by only 1 percentage point. Neither mean time spent below SpO₂ 88% nor oxygen desaturation index (ODI) worsened postoperatively (mean time spent below oxygen saturation of 88%, 27.8 ± 7.85 vs 11.2 ± 5.2, P = .03; mean ODI, 29.6 ± 5.2/h vs 21.0 ± 5.4/h, P = .10). Mean obstructive apnea hypopnea index (AHI) was no worse (40.6 ± 4.7/h to 28.7 ± 4.2/h, P = .02), with only 2 patients experiencing an obstructive AHI >20% more severe than baseline. Only 1 patient demonstrated a clinically meaningful increase in central AHI on PON 1.

CONCLUSIONS

Overall, AHI and measures of nocturnal hypoxemia are stable, if not improved, on PON 1 following HGNS implantation. These findings support the safety of same-day discharge following implantation of the hypoglossal nerve stimulator.

Neuromodulation in Obstructive Sleep Apnea

Epidemiological studies show a steady rise in the prevalence of obstructive sleep apnea (OSA). Untreated OSA is responsible for numerous chronic health conditions, motor vehicle, and workplace-related accidents leading to substantial economic burden both to the individual and society. Multiple causes for OSA and a wide range of consequences has made its diagnosis and treatment difficult. Obstructive sleep apnea may be caused by anatomical variation, increased collapsibility of the upper airway, low sleep arousal threshold, and exaggerated response to desaturation. Lifestyle changes, anatomical corrective surgeries, and oral appliances have been used but patient compliance is poor as it interferes in the daily routine. Neuromodulation is a promising functional modifying option that addresses the cause of obstructive sleep apnea at multiple levels.