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.

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.

The effect of velar collapse patterns on unilateral upper airway stimulation therapy

PURPOSE

Hypoglossal nerve stimulation is a promising alternative therapy for patients with obstructive sleep apnea with continuous positive airway pressure intolerance or failure. Previous studies concluded that a velar complete concentric collapse might prohibit a good therapeutic outcome. However, certain patients have an upper velar anteroposterior collapse and a lower velar complete concentric collapse. The effect of this velar collapse pattern is unknown, preventing evidence-based decision-making for these patients. This study aimed to compare the results of upper airway stimulation therapy in these patients to patients with a pure anteroposterior velar collapse.

METHODS

A retrospective single-center cohort study was performed. Patients were included who were implanted with an upper airway stimulation device and had a 1-year follow-up.

RESULTS

Of 66 patients, 10 had an upper velar anteroposterior collapse and lower velar complete concentric collapse. Fifty-six patients had a complete or partial velar anteroposterior collapse. At follow-up, all respiratory outcomes were similarly changed between the two groups. The mean apnea and hypopnea index reduced equally (26.9 events/hour vs. 23.9 events/hour, 95% CI (-5.0, 11.0), p = 0.46). A similar decrease in the oxygen desaturation index of ≥ 4% was observed (12.0/hour versus 11.5/hour, 95% CI (-8.7, 9.7) p = 0.92) CONCLUSION: Patients with an upper velar anteroposterior collapse and a lower velar complete concentric collapse are suitable candidates for upper airway stimulation therapy. In these patients, the lower velum may represent a transition zone between the anteroposterior collapse of the upper velum and the lateral collapse of the oropharynx, instead of being a real concentric collapse.

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.

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.

Fuzzy Representation of Principal's Preferences in Inspire Negotiation Support System

We consider the negotiation problem, in which an agent negotiates on behalf of a principal. Our considerations are focused on the Inspire negotiation support system in which the principal’s preferences are visualised by circles. In this way, the principal describes the importance of each negotiation issue and the relative utility of each considered option. The paper proposes how this preference information may be implemented by the agent for determining a scoring function used to support decisions throughout the negotiation process. The starting point of our considerations is a discussion regarding the visualisation of the principal’s preferences. We assume here that the importance of each issue and the utility of each option increases with the size of the circle representing them. The imprecise meaning of the notion of “circle size” implies that in a considered case, the utility of an option should be evaluated by a fuzzy number. The proposed utility fuzzification is justified by a simple analysis of results obtained from the empirical prenegotiation experiment. A novel method is proposed to determine trapezoidal fuzzy numbers, which evaluates an option’s utility using a series of answers given by the participants of the experiment. The utilities obtained this way are applied to determine the fuzzy scoring function for an agent. By determining such a common generalised fuzzy scoring system, our approach helps agents handle the differences in human cognitive processes associated with understanding the principal’s preferences. This work is the first approach to fuzzification of the preferences in the Inspire negotiation support system.

The Hypoglossal Nerve Stimulation as a Novel Therapy for Treating Obstructive Sleep Apnea-A Literature Review

Obstructive sleep apnea (OSA) is a common sleep disorder that affects all age groups and is associated with many co-morbid diseases (especially cardiovascular diseases). Continuous positive airway pressure (CPAP) is the gold standard for treating OSA. However, adherence to PAP therapy has been a major challenge with an estimated adherence between 20% and 80%. Mandibular advancement devices (MAD) are a good alternative option if used in the appropriate patient. MAD are most effective in mild and moderate OSA but not severe OSA. Surgical options are invasive, not appropriate for severe OSA, and associated with pain and long healing time. Hypoglossal nerve stimulation (HGNS), or upper airway stimulation (UAS), is a novel therapy in treating moderate and severe degrees of OSA in patients who cannot tolerate CPAP therapy. We reviewed the MEDLINE (PubMed) database. The search process yielded 303 articles; 31 met the inclusion and exclusion criteria and were included. We concluded that hypoglossal nerve stimulation is a very effective and novel alternative therapy for moderate and severe OSA in patients who cannot tolerate CPAP therapy. Adherence to HGNS is superior to CPAP. However, more developments are needed to ensure the highest safety profile.

Adverse events associated with the Inspire implantable hypoglossal nerve stimulator: A MAUDE database review

BACKGROUND

Implantable hypoglossal nerve stimulation (HNS) has been found to be a safe and effective therapy for patients with obstructive sleep apnea, and patient adherence to treatment has been found to be as high as 86% after 12 months of therapy.

OBJECTIVE

The purpose of this study is to review the medical device reports (MDRs) submitted to the Food and Drug Administration's (FDA) Manufacturer and User Device Facility Experience (MAUDE) database to identify adverse events related to HNS therapy that could hinder compliance.

METHODS

A search of the FDA MAUDE database was conducted using the product code "MNQ" for "Inspire stimulator for sleep apnea." Reports of adverse events associated with Inspire for sleep apnea from January 2000 to May 2020 were included for analysis. From these included reports, event variables were collected, including event setting, adverse event to patient, iatrogenic injury, device malfunction, interventions, and root causes. Results were compiled and reviewed.

RESULTS

The search query yielded 180 reports that met inclusion criteria, containing a total of 196 adverse events. The most commonly reported adverse events to patients were infection (n = 50, 34.2%), neuropraxia (n = 22, 15.1%) and hematoma/seroma (n = 17, 11.6%). A total of 83 adverse events (42.3%) required reoperation. The most common reoperations performed for adverse events to patients were explantation (n = 30, 46.2%) and device repositioning/lead revision (n = 24, 36.9%), while the most common reoperation performed for device malfunctions was device replacement (n = 10, 55.6%).

CONCLUSION

In attempting to further improve patient compliance, understanding these device malfunctions and adverse events related to HNS implantation or usage is crucial for the identification of potential causes of patient non-adherence.

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.

The Rise of Upper Airway Stimulation in the Era of Transoral Robotic Surgery for Obstructive Sleep Apnea

Introduced in 2010, transoral robotic surgery (TORS) is recognized as an effective treatment of moderate to severe obstructive sleep apnea (OSA) in the setting of lymphoid and muscular tongue base hypertrophy. Upper airway stimulation (UAS) or hypoglossal nerve stimulation has emerged as a promising treatment of patients with moderate to severe OSA who have failed continuous positive airway pressure. UAS has shown favorable success rates and low morbidity compared with traditional soft tissue and skeletal framework surgery. UAS is in its infancy as a surgical procedure and concerns exist regarding narrow candidacy criteria, postimplant device titration, and durability of treatment response.

Hypoglossal nerve stimulator generator migration: INSPIRE device reimplantation with parallels to cardiac implantable electronic devices

Implantation rates of hypoglossal nerve stimulators, such as INSPIRE, are increasing. The device is still in its early stages of complication reporting, which to date includes implant related infection requiring device removal, and stimulation lead cuff dislodgement requiring replacement. Here we present a 48-year-old female who experienced generator migration and stimulator lead tension requiring an additional operation in order to resecure the generator device. This proved unsuccessful and a second surgery was performed with complete relocation of the device generator to inhibit device migration. This is the first documented case of INSPIRE migration to date, though the implant generator has comparable likeness to cardiovascular implantable electronic devices (CIEDs) where migration risk factors are better studied. Given our patient's case, we identify obesity and abundant breast tissue as potential risk factors for device migration. We believe such factors can be identified prior to initial device implantation to avoid migration and the need for surgical revision. Superior positioning of the generator proved successful, and can be a solution in those with similar body habitus as TYRX pouching and additional security sutures were ineffective. Also, for revisions requiring tunneling of the stimulation lead as in this case we recommend the use of zero degree endoscope for ease of adhesion lysis.