Iatrogenic pneumothorax during hypoglossal nerve stimulator implantation

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Intervention

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Trial Registration

ClinicalTrials.gov Identifier: NCT02263859.

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.

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.

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.

Adverse Events in Hypoglossal Nerve Stimulator Implantation: 5-Year Analysis of the FDA MAUDE Database

OBJECTIVE

Use of hypoglossal nerve stimulator implantation has dramatically improved the surgical treatment of multilevel airway collapse during obstructive sleep apnea (OSA). Understanding causes of adverse events and their impact on patients undergoing stimulator implantation will help improve patient preparation and surgical practices to avoid future complications.

STUDY DESIGN

This study is a retrospective review of the US Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database, a publicly available voluntary reporting system.

SETTING

National patient event database.

METHODS

The MAUDE database was searched for reports associated with the terms "hypoglossal nerve stimulator" and "Inspire," being the only currently FDA-approved system for upper airway stimulation for OSA. All records were searched with the events limited in dates between May 2014 and September 2019.

RESULTS

A total of 132 patient reports were identified over the 5-year inclusion period, containing 134 adverse events. The reported adverse events resulted in 32 device revision procedures as well as 17 explantations. Device migration and infection were 2 of the most commonly reported adverse events. Complications not witnessed in previous large-scale clinical trials included pneumothorax, pleural effusion, and lead migration into the pleural space.

CONCLUSION

Previous data have demonstrated hypoglossal nerve stimulator implantation results in reliable OSA improvement. However, a number of technical difficulties and complications still exist during the perioperative period, which should be communicated to patients during the surgical consent process.

Base of Tongue Surgery for Obstructive Sleep Apnea in the Era of Neurostimulation

Retroglossal collapse is commonly seen in patients with obstructive sleep apnea. The role of upper airway stimulation surgery for these patients continues to evolve. However, base of tongue reduction surgery continues to have usefulness for appropriately selected patients with obstructive sleep apnea. Specific tongue base approaches may vary in response to patient and surgeon preferences and be used in multilevel surgery where appropriate. Key factors include patient age, willingness to undergo device implantation, and preferences for outpatient versus inpatient procedure, single procedure versus multiple, and tolerance for various procedure-specific postoperative restrictions and potential complications.