Success of Hypoglossal Nerve Stimulation Using Mandibular Advancement During Sleep Endoscopy

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.

The clinical application progress and potential of drug-induced sleep endoscopy in obstructive sleep apnea

Background and Objective: Obstructive sleep apnoea (OSA) is characterized by nocturnal repetitive upper airway (UA) collapse. For sleep physicians, the recognition of UA collapse characteristics is critical for understanding OSA mechanisms and developing individualized treatment plans. Drug-induced sleep endoscopy (DISE) is an exam during simulated sleep that allows the dynamic assessment of the UA of individuals with OSA. The initial recognition of DISE was to locate the sites of UA obstruction and direct the surgical selection of OSA since it was introduced in the 1990s. After approximately 30 years of studies, based on advances in endoscopic operative techniques and innovative treatments of OSA, DISE had been performed to explore mechanisms and comprehensive treatments related to UA collapse. Methods: This article reviewed contemporary DISE advances, including indications and contraindications, technique of induced sleep, endoscopic operation, UA characteristics classification.Results and Conclusions: Precise selection based on the association between collapse patterns and treatment modalities, such as continuous positive airway pressure, oral appliance, positional therapy, robotic surgery and neurostimulator implanting, is the future research prospect based on DISE.Key messagesDISE provides sleep physicians with valuable information about the upper airway collapse characteristics and dynamic changes during sleep.The studies based on DISE findings improve the selectivity and efficiency of treatment modalities, including classical therapies such as continuous positive airway pressure, oral appliance, positional therapy, and innovative therapies such as neurostimulator implanting and robotic surgery, promote the advancement of OSA precision medicine.

Noninvasive electrical stimulation of oropharyngeal muscles in obstructive sleep apnea

Introduction: Continuous positive airway pressure (CPAP) therapy remains the standard treatment for obstructive sleep apnea. However, its proven effect is useless if the patient does not tolerate the treatment. The electrical stimulation approach has been investigated for several decades now and it seems that the implantable devices for invasive electrical stimulation of hypoglossal nerve are viewed as effective with some of them already approved for human use.Areas covered: in this review, we intent to summarize the existing records of noninvasive stimulation in sleep apnea to make the scientific community aware of the details before deciding on its future. We believe that this is a battle still to fight and more could be done bearing in mind the safety of this method.Expertopinion: noninvasive electrical stimulation has been left behind based on few, small and inconsistent studies using different stimulation parameters. These studies are difficult to compare and to draw conclusions.Electrical stimulation is a field for research in the treatment of obstructive sleep apnea, with many aspects still to be discovered, and which may become a therapeutic alternative to the use of CPAP in certain patients.

Obstruction level associated with outcome in hypoglossal nerve stimulation

Purpose

Selective hypoglossal nerve stimulation (sHNS) constitutes an effective surgical alternative for patients with obstructive sleep apnea (OSA). sHNS results in tongue protrusion and consecutive alleviation of obstructions at the tongue base level (lower obstructions). Furthermore, obstructions at the soft palate level (upper obstructions) may be prevented through palatoglossal coupling as seen on sleep endoscopy. However, it has not been studied if the distribution of obstruction level during a whole night measurement is a relevant factor for the treatment outcome.

Methods

Obstruction levels were measured with a manometry system during a whole night of sleep in 26 patients with OSA (f = 1, m = 25; age 59.4 ± 11.3; BMI = 29.6 ± 3.6) either before (n = 9) or after sHNS implantation (n = 12). Five patients received a measurement before and after implantation. Obstructions were categorized into velar (soft palate and above), infravelar (below soft palate), and multilevel obstructions. An association between obstruction level and treatment outcome was calculated.

Results

The mean distribution of preoperative obstruction level could be divided into the following: 38% velar, 46% multilevel, and 16% infravelar obstructions. Patients with a good treatment response (defined as AHI < 15/h and AHI reduction of 50%) had fewer preoperative velar obstructions compared to non-responder (17% vs. 54%, p-value = 0.006). In patients measured after sHNS implantation, a significantly higher rate of multilevel obstructions per hour was measured in non-responders (p-value = 0.012).

Conclusions

Selective hypoglossal nerve stimulation was more effective in patients with fewer obstructions at the soft palate level. Manometry may be a complementary diagnostic procedure for the selection of patients for HNS.

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.

Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulation Outcomes: A Multicenter Cohort Study

OBJECTIVES/HYPOTHESIS

To determine the association between findings of blinded reviews of preoperative drug-induced sleep endoscopy (DISE) and outcomes of hypoglossal nerve stimulation (HNS) for obstructive sleep apnea (OSA).

STUDY DESIGN

Cohort study.

METHODS

A retrospective, multicenter cohort study of 343 adults who underwent treatment of OSA with HNS from 10 academic medical centers was performed. Preoperative DISE videos were scored by four blinded reviewers using the VOTE Classification and evaluation of a possible primary structure contributing to airway obstruction. Consensus DISE findings were examined for an association with surgical outcomes based on therapy titration polysomnogram (tPSG). Treatment response was defined by a decrease of ≥50% in the apnea-hypopnea index (AHI) to <15 events/hour.

RESULTS

Study participants (76% male, 60.4 ± 11.0 years old) had a body mass index of 29.2 ± 3.6 kg/m² . AHI decreased (35.6 ± 15.2 to 11.0 ± 14.1 events/hour; P < .001) on the tPSG, with a 72.6% response rate. Complete palate obstruction (vs. none) was associated with the greatest difference in AHI improvement (-26.8 ± 14.9 vs. -19.2 ± 12.8, P = .02). Complete (vs. partial/none) tongue-related obstruction was associated with increased odds of treatment response (78% vs. 68%, P = .043). Complete (vs. partial/none) oropharyngeal lateral wall-related obstruction was associated with lower odds of surgical response (58% vs. 74%, P = .042).

CONCLUSIONS

The DISE finding of primary tongue contribution to airway obstruction was associated with better outcomes, whereas the opposite was true for the oropharyngeal lateral walls. This study suggests that the role for DISE in counseling candidates for HNS extends beyond solely for excluding complete concentric collapse related to the velum.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:1676-1682, 2021.

Use of overnight pulse oximetry and a type 3 sleep study to titrate hypoglossal nerve stimulation therapy

NONE

This is a case series of 3 patients with moderate-severe OSA who were PAP-intolerant and underwent implantation of the hypoglossal nerve stimulator. All patients recorded baseline overnight pulse oximetry without the hypoglossal nerve stimulator and at least 1 night at each hypoglossal nerve stimulator setting as they up-titrated the device at home. Because of the impact of the novel coronavirus on sleep laboratories, all patients proceeded directly to type 3 sleep studies performed at a single setting determined by a combination of self-reported improvement and pulse oximetry data.