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

Troubleshooting Upper Airway Stimulation Therapy Using Drug-Induced Sleep Endoscopy

OBJECTIVE

This study assesses the utility of drug-induced sleep endoscopy (DISE) in guiding further treatment for patients with obstructive sleep apnea (OSA) who have difficulty tolerating upper airway stimulation (UAS) or have inadequate response to therapy.

STUDY DESIGN

We conducted a retrospective analysis of UAS patients at our institution who underwent DISE, post-UAS, and evaluated the efficacy of different electrode configurations and maneuvers.

SETTING

A tertiary care hospital.

METHODS

Out of 379 patients who received UAS therapy, 34 patients who underwent DISE post-UAS (DISE-UAS) were included. Palatal coupling (PC) was assessed with UAS stimulation alone, jaw thrust alone, and both simultaneously during DISE.

RESULTS

Among 34 patients, 5 had suboptimal adherence to UAS therapy, 19 had suboptimal therapy efficacy with residual OSA burden, and 10 had both. During DISE-UAS, PC was observed in 7 patients (21%) with UAS stimulation alone, 9 patients (26%) with jaw thrust alone, and 8 patients (24%) with both maneuvers combined. Notably, 10 patients (29%) did not exhibit PC with any maneuver. Based on DISE-UAS findings, 13 patients were recommended oral appliance therapy (OAT), and 8 patients underwent further surgical interventions.

CONCLUSION

DISE-UAS is a valuable adjunct in troubleshooting UAS therapy for patients intolerant to CPAP or with suboptimal therapy efficacy. This study provides an algorithm for targeted multimodality therapy based on DISE findings, facilitating personalized management approaches.

Should lateral wall collapse be a contraindication for hypoglossal nerve stimulation?

OBJECTIVE

The purpose of this study is to examine how lateral wall collapse affects treatment outcomes for hypoglossal nerve stimulation (HNS) patients.

METHODS

Patients (n = 111) queried from a single surgeon's database of HNS cases were divided into groups based on their degree of oropharyngeal lateral wall collapse noted on drug-induced sleep endoscopy (DISE): Complete, Partial, None. For each group, apnea hypopnea index (AHI) reduction, Epworth Sleepiness Scale (ESS) score, stimulation voltage, average nightly usage, need for alternate device configuration/awake sleep endoscopy, and rate of surgical success were collected. Patients with Complete collapse were compared to those with Partial/None via Student's t-tests and Pearson's Chi-square test.

RESULTS

Of the 111 eligible patients, 45 had complete, 30 partial, and 36 had no lateral oropharyngeal wall collapse. There were no statistically significant differences found between the Complete and Partial/None groups in terms of age, BMI, sex, AHI (pre and post-op), ESS (pre and post-op), voltage, alternate device configuration, or nightly adherence. Notably, a significantly greater number of the Partial/None group had surgical success (84.84 % vs 66.67 %, p = 0.024).

CONCLUSIONS

Patients with Partial/None oropharyngeal collapse were significantly more likely than patients with Complete lateral wall collapse to see surgical success. There are many factors to weigh when assessing a patient's surgical candidacy, it is clear that complete lateral wall collapse at the level of the oropharynx is a negative predictor for success in HNS.

Reduced usage of upper airway stimulation therapy in patients with comorbid insomnia and obstructive sleep apnea

STUDY OBJECTIVES

Upper airway stimulation (UAS) is a hybrid surgical-medical device used to treat moderate-to-severe obstructive sleep apnea (OSA). Comorbid insomnia and OSA (COMISA) is present in ∼50% of these patients. Our aim was to study UAS outcomes and adherence in patients with COMISA.

METHODS

A retrospective review of 379 patients with OSA who underwent UAS implantation at a single institution between 2014 and 2021. Demographics, OSA severity metrics, and insomnia data were collected. Patients were categorized into OSA alone (OSAa) or COMISA. Objective adherence data were collected from device downloads during follow-up. Data were analyzed with using R Studio (R Foundation for Statistical Computing, Vienna, Austria) and Prism (Boston, MA, USA).

RESULTS

Of the 274 patients included, 148 had COMISA (54.0%) and 126 OSAa (46.0%). Average follow-up time was 2.5 years and OSAa had more males than COMISA (P < .001). Patients with COMISA had higher insomnia severity index scores than OSAa preoperatively (16 vs 8.7; P = .003). All groups showed significant decreases in objective and self-reported OSA outcomes postoperatively, but there was no difference between COMISA and OSAa. Patient with COMISA had decreased device usage (4.9 vs 5.8 h/night; P = .015) and paused therapy more often than patients with OSAa (1.4 vs 0.4 pauses/night; P < .001). Multivariate linear regression, when controlling for sex as a covariate, showed insomnia to be an independent predictor of lower UAS hours/night and more pauses/night (P < .01).

CONCLUSIONS

Patients with COMISA use UAS therapy for shorter durations and require more breaks from therapy when compared with those with OSAa. Future research is needed to explore the underlying mechanism and improve UAS treatment adherence in patients with COMISA.

CITATION

Kaffenberger TM, Chandna M, Kaki P, et al. Reduced usage of upper airway stimulation therapy in patients with comorbid insomnia and obstructive sleep apnea. J Clin Sleep Med. 2023;19(12):1997-2004.

Hypoglossal Nerve Stimulation Therapy

Hypoglossal nerve stimulation (HNS) has been shown to be a safe alternative in the treatment of moderate-to-severe obstructive sleep apnea (OSA). A recent meta-analysis of 12 studies by Costantino et al. indicated the surgical success rates at 55-75%, a reduction of the apnea hypopnea index (AHI) of 18 events/h, and a reduction of the Epworth Sleepiness Scale (ESS) of 2.9-5.3. After animal studies in the 1970s, the first trial on humans to decrease upper airway resistance by transcutaneous electrical stimulation of the genioglossus was reported in 1989. A separate stimulation of protruding and retracting muscles was realized in 1995 by fine-wire electrodes that were placed into the tongue transoral. Over the next years, several companies developed implantable devices for hypoglossal stimulation in OSA. Initially, devices were developed that used unilateral stimulation of the hypoglossal nerve. In 2014, a device for unilateral respiratory frequency-controlled hypoglossal stimulation finally received FDA approval after a successful phase III trial. In recent years, a device for bilateral breath rate-independent stimulation of the hypoglossal nerve has been added to these approaches as a new development. Accordingly, hypoglossal nerve stimulation, on the one hand, is now an established tool for patients with OSA when standard treatments are not satisfactory. Beyond that, hypoglossal stimulation is undergoing a continuous and impressive development like hardly any other field of surgical therapy for OSA.