Hypoglossal Nerve Stimulator Outcomes for Patients Outside the U.S. FDA Recommendations

Increased Body Mass Index Correlates with Less Favorable Postoperative Outcomes After Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea: A Retrospective Cohort Study

OBJECTIVE

Obstructive sleep apnea is associated with high morbidity. Hypoglossal nerve stimulation (HNS) has become a novel (neuro-) surgical treatment strategy for obstructive sleep apnea, demonstrating good success rates. Beyond predefined inclusion and exclusion criteria, no precise data are available, enabling individual preoperative risk assessment. To improve preoperative risk stratification, this study analyzed individual patient factors that affect outcomes of HNS.

METHODS

Fourteen patients treated with unilateral HNS were analyzed retrospectively. Assessed risk factors included: hypertension, diabetes mellitus, depression, smoking, alcohol consumption, body mass index (BMI), and disease duration. Treatment success was defined as a reduction in the postoperative apnea-hypopnea index (AHI) to ≤20 events/hour, with a relative reduction of at least 50% compared to baseline.

RESULTS

A significant reduction in the postoperative apnea-hypopnea index was observed in all patients (P < 0.0001). BMI correlated significantly with postoperative AHI scores (95% confidence interval, 0.1519-0.8974; P = 0.018). Significant treatment success was observed in 50% of patients. Compared with the "Excellent Responder group," the "Responder group" demonstrated a significantly higher BMI (95% confidence interval, 1.174-6.226; P = 0.0078). Diabetes, hypertension, disease duration, smoking, depression, and alcohol consumption were not significantly associated with AHI reduction.

CONCLUSIONS

Our findings suggest that BMI may be an independent risk factor for the response to HNS, with patients who had less benefit from therapy having significantly higher BMI than "Excellent Responders." Therefore, carefully selecting patients is crucial in obtaining optimal outcomes with HNS therapy, especially those with a high BMI.

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.

Long-term trends in body mass index throughout upper airway stimulation treatment: does body mass index matter?

STUDY OBJECTIVES

Upper airway stimulation is a surgical option for patients with obstructive sleep apnea who fail other forms of noninvasive treatment. Current guidelines recommend a baseline body mass index (BMI) below 32 kg/m2 for eligibility. In this study, we identify trends in BMI before and after upper airway stimulation to characterize the influence of BMI on treatment success.

METHODS

Patients underwent upper airway stimulation implantation between 2016 and 2021. Sleep study data were collected from preoperative and most recent postoperative sleep study. BMI data were collected and compared across the following time points: preoperative sleep study (BMI-1), initial surgeon consultation (BMI-2), surgery (BMI-3), titration polysomnogram (BMI-4), and second postoperative sleep study (BMI-5). Patients were categorized into groups (BMI ≥32 [BMI32], 25 ≤ BMI <32 [BMI25], BMI <25 [BMI18]) based BMI-1, and clinical outcomes were compared.

RESULTS

253 patients were included. The BMI32 group showed a significant decrease in BMI between BMI-1 and BMI-3 (33.9 vs 32.2; P < .001) and a significant increase in BMI between BMI-3 and BMI-5 (32.2 vs 33.0; P = .047). Apnea-hypopnea index improvement and treatment success rate were not significantly different between groups. On univariate and multivariable logistic regression, a lower BMI-5 was significantly predictive of treatment success (odds ratio: 0.88; 95% confidence interval: 0.79-0.97; P = .016). BMI-5 was also significantly associated with improvement in apnea-hypopnea index (P = .002). Other BMI time points were not associated with measures of treatment success.

CONCLUSIONS

Reduced BMI after upper airway stimulation implantation, as opposed to baseline BMI, predicted treatment success. These findings may guide patient counseling, with implications for long-term adherence and therapy success.

CITATION

Renslo B, Virgen CG, Sawaf T, et al. Long-term trends in body mass index throughout upper airway stimulation treatment: does body mass index matter? J Clin Sleep Med. 2023;19(6):1061-1071.

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.

Maxillomandibular Advancement and Upper Airway Stimulation for Treatment of Obstructive Sleep Apnea: A Systematic Review

This systematic review aimed to comparatively evaluate the efficacy and safety of maxillomandibular advancement (MMA) and upper airway stimulation (UAS) in obstructive sleep apnea (OSA) treatment. A MEDLINE and Embase database search of articles on MMA and/or UAS for OSA was conducted. Twenty-one MMA studies and nine UAS studies were included. All the MMA studies demonstrated a reduction in apnea hypopnea index (AHI) postoperatively, and success rates ranged from 41.1% to 100%. Ten MMA studies reported pre- and postoperative Epworth sleepiness scale (ESS), and all but one study demonstrated a reduction in ESS. In the UAS studies, all but one demonstrated a reduction in AHI, and success rates ranged from 26.7% to 77.8%. In the eight UAS studies reporting pre- and postoperative ESS, an ESS reduction was demonstrated. No studies reported any deaths related to MMA or UAS. The most common postoperative complications after MMA and UAS were facial paresthesia in the mandibular area and discomfort due to electrical stimulation, respectively. This systematic review suggests that both MMA and UAS are effective and generally safe therapies for OSA. However, due to the limitations of the included studies, there is no evidence yet to directly compare these two procedures in OSA treatment.

Obstructive Sleep Apnea and Cardiovascular Diseases: Sad Realities and Untold Truths regarding Care of Patients in 2022

Obstructive sleep apnea (OSA) is one of the most common and serious sleep-related breathing disorders with a high prevalence among patients with cardiovascular (CV) diseases. Despite its widespread presence, OSA remains severely undiagnosed and untreated. CV mortality and morbidity are significantly increased in the presence of OSA as it is associated with an increased risk of resistant hypertension, heart failure, arrhythmias, and coronary artery disease. Evaluation and treatment of OSA should focus on recognizing patients at risk of developing OSA. The use of screening questionnaires should be routine, but a formal polysomnography sleep study is fundamental in establishing and classifying OSA. Recognition of OSA patients will allow for the institution of appropriate therapy that should alleviate OSA-related symptoms with the intent of decreasing adverse CV risk. In this review, we focus on the impact OSA has on CV disease and evaluate contemporary OSA treatments. Our goal is to heighten awareness among CV practitioners.

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.

Representation of Race and Sex in Sleep Surgery Studies

OBJECTIVE

Obstructive sleep apnea (OSA) is a highly prevalent disorder with many treatment modalities, including surgical intervention. While OSA is known to be more prevalent in males and Black Americans, the representation of race and sex in sleep surgery studies is unknown. The aim of this systematic review is to assess the race and sex demographics represented in sleep surgery studies relative to known OSA demographics.

DATA SOURCES

PubMed, MEDLINE, and OVID databases.

REVIEW METHODS

A systematic review was conducted to identify studies published between 2016 and 2020 that investigated sleep outcomes following nonnasal surgical intervention for OSA in adults. Pooled racial, ethnic, and sex data of the enrolled subjects in selected studies were analyzed.

RESULTS

The 148 included studies comprised 13,078 patients. Of the 137 studies that reported sex, 84.0% of participants were male, exceeding the population prevalence of OSA in males, which is estimated at 66%. Only 13 studies reported racial/ethnic demographic data. Of these, 87.8% of patients were White. Out of 30 studies of primarily American patients, only 4 reported race demographic data, with an average of 82.8% White participants.

CONCLUSION

There is a racial/ethnic and sex inclusion bias among sleep surgery studies. Future studies should better document the demographics of enrolled participants as well as recruit participants who better represent the demographics of adults with OSA in the general population.

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.

Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions and research gaps. 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.

No changes in nocturnal respiration with hypoglossal neurostimulation therapy for obstructive sleep apnoea

STUDY OBJECTIVES

We initiated Hypoglossal Neurostimulation therapy (HGNS) at the Helsinki University Hospital in late 2014. Here, we report our experience.

METHODS

We included all 15 HGNS patients. All patients had previously failed both CPAP and oral appliance therapy for sleep apnoea. Overnight polysomnography parameters were analysed before and at 1.5 years with HGNS.

RESULTS

Mean ± SD patient age was 53 ± 6 years; 2 women and 13 men were included. Mean ± SD efficient CPAP level was 11.4 ± 3.4 cm H₂ O. Implantation technically succeeded in all patients. There were no significant changes of AHI and ODI4 after HGNS [median (quartile) 29.2/h (19.8-38.7) versus 30.1/h (15.6-52.6) and 15.0/h (5.9-20) versus 12.5/h (6.9-30.2) respectively].

CONCLUSION

We did not observe significant changes in AHI and ODI4 indices with HGNS therapy. Larger multicentre randomised controlled trials are necessary before wider international use of HGNS.

Hypoglossal Nerve Stimulation Therapy for the Treatment of Obstructive Sleep Apnea

Hypoglossal nerve stimulation (HGNS) therapy was approved in 2014 for the treatment of obstructive sleep apnea in patients who are intolerant to continuous positive airway pressure (CPAP) therapy, which is reported in up to 40-60% of patients. This therapy works via direct neurostimulation of the hypoglossal nerve in synchrony with respiration, to open the airway via tongue stiffening and protrusion. Studies have demonstrated significant reductions in both respiratory parameters such as disordered breathing indices, as well as subjective sleep complaints, such as daytime sleepiness, with the use of this therapy. This has increased the repertoire of treatment options for sleep providers to recommend to those patients that are intolerant to CPAP therapy.

Hypoglossal Nerve Stimulation in the Treatment of Obstructive Sleep Apnea: Patient Selection and New Perspectives

Hypoglossal nerve stimulation (HNS) is an increasingly widespread OSA treatment. It is a non-anatomical modifying surgery able to achieve an adequate objective and subjective result with a reasonable complication rate. HNS exploits the neurostimulation to reduce upper airway collapsibility providing a multilevel upper airway improvement within a single procedure. Proper patient selection has a fundamental role in determining an adequate long-term clinical outcome. All patient candidates for HNS undergo a standard comprehensive sleep medicine assessment and upper airway surgical examination. Several features should be assessed preoperatively in order to predict patients' response to HNS treatment. In particular, the assessment of OSA severity, BMI > 32 Kg/m², collapse pattern during drug-induced sleep endoscopy (DISE), and many other parameters, is central for a good patient selection and customization of OSA treatment. HNS is indeed one of the most promising tools in the widespread context of personalized sleep medicine. HNS is an adjustable medical device that could be titrated in order to improve HNS effectiveness, maintaining patient comfort. Moreover, HNS provides the opportunity for patients to play an active role in their own care, with a potential improvement in therapy adherence and efficacy. This review summarizes the current evidence in patient selection for HNS, highlighting the reasons behind the optimistic future of this OSA treatment in the context of personalized medicine.