Anatomic-Based Technique for Sensing Lead Placement in Hypoglossal Stimulator Implantation.

Placement of the sensing lead can be challenging in obese and Down syndrome patients. This article presents an alteration in technique for its placement for these patient populations. Laryngoscope, 2024.

How we measure hypoglossal nerve stimulator outcome matters: titration versus single amplitude efficacy sleep studies.

STUDY OBJECTIVES: Hypoglossal nerve stimulation (HGNS) is a common treatment for obstructive sleep apnea (OSA). Objective assessment of HGNS efficacy measures apnea-hypopnea index (AHI) by multi-amplitude titration polysomnography (tPSG) and/or a single amplitude efficacy sleep study (eHST). Both tests have been used to determine efficacy despite significantly different protocols. This project's aim was to determine differences in objective outcomes in HGNS patients who underwent both tPSG and eHST post-operatively. METHODS: Data from 379 consecutive HGNS patients were retrospectively reviewed. Inclusion requirements were a pre-operative sleep study, a post-operative tPSG, and then an eHST, which at our institution is a type 3 home study. AHI mean and differences were calculated. Wilcoxon rank sum tests were used to analyze differences between tPSG and eHST. Sher15 criteria (post-operative AHI≤15 events/hour and ≥50% reduction from baseline) was calculated and compared by χ2 tests. RESULTS: Ultimately 61 patients met inclusion criteria with an average pre-operative AHI=33.2. When comparing the subject's tPSG versus eHST, tPSG AHI was significantly lower (AHI=8.8 versus AHI=17.6; respectively, p<0.001). There was also a difference in the percentage of patients that met Sher15 criteria when using tPSG (80.3%) versus eHST AHI (45.9%). CONCLUSIONS: HGNS patient's postoperative tPSG AHI was significantly lower than their eHST outcome. This work highlights the importance of reporting the type of post-operative study used in evaluating HGNS efficacy and the need for single amplitude, full-night studies to assess HGNS efficacy more accurately.

CO2 laser lingual tonsil reduction as a treatment for tongue discomfort during hypoglossal nerve stimulation: a case report.

The purpose of this investigation is to demonstrate a multimodality approach to the surgical management of obstructive sleep apnea. Hypoglossal nerve stimulator (HGNS) implantation has been a life-changing procedure for many patients with obstructive sleep apnea. When activated it produces tongue protrusion via electrical stimulation of the hypoglossal nerve. This advances the lingual tonsil, making the pharynx diameter greater. Unfortunately, for some patients the electrical stimulation required is too high and awakens the patient. In such cases the patient's fragmented sleep is not improved with the hypoglossal nerve stimulator. Here we present a case where hypoglossal nerve stimulator and CO2 laser lingual tonsil reduction are used in conjunction to reduce the hypoglossal nerve stimulator setting required for airway patency, thereby allowing the patient to sleep through the night. For those patients who are unable to tolerate hypoglossal nerve stimulator settings, a combined approach with lingual tonsil reduction may be an alternative. CITATION: Fontenot A, Liu SYC, Dewan K. CO2 laser lingual tonsil reduction as a treatment for tongue discomfort during hypoglossal nerve stimulation: a case report. J Clin Sleep Med. 2024;20(11):1857-1861.

Longitudinal Analysis of Hypoglossal Nerve Stimulator Therapy Uptitration Using Cloud-Based Usage Data.

This preliminary study investigates hypoglossal nerve stimulator (HNS) amplitude changes and usage patterns during the initial HNS uptitration period to characterize when patients achieve their therapeutic amplitude. HNS therapy amplitudes, duration, and pause times were examined across the first 4 months of implant use. Average HNS therapy amplitude increased monthly from baseline (0.7 ± 0.3 V) to the first (1.1 ± 0.3 V), second (1.4 ± 0.4 V), third (1.7 ± 0.5 V), and fourth months (1.8 ± 0.5 V) (P < .001). After 4 months, 60% had reached a therapeutic amplitude. Average therapeutic amplitude was greater for patients who did not achieve therapeutic amplitude by month 4 than for those who did (2.6 vs 1.6 V; P < .05). Body mass index, baseline apnea-hypopnea index, respiratory disturbance index, and initial HNS amplitude did not differ between the 2 groups. Predictors for therapeutic amplitude and other usage patterns require further investigation.

Video-assisted thoracoscopic surgery retrieval of a migrated unilateral hypoglossal nerve stimulator sensor lead.

Obstructive sleep apnea is a common chronic condition typically treated with positive airway pressure. However, many patients have difficulty with adherence to this therapy, and for some, implantation of a hypoglossal nerve stimulator has become an option. Although device implantation is generally well-tolerated, a minority of patients will experience serious adverse events. Here we report the unusual complication of the sensor lead migrating to the costophrenic angle and invading the pleural space. Nine months after original implantation, the sensor lead malfunctioned and was found to be displaced. Initial explantation and reimplantation of a new device resulted in the inability to find a portion of the lead. Reimaging showed the missing lead at the costophrenic angle, and the patient underwent thoracoscopic removal. He resumed therapy with the new device without difficulty. This case demonstrates the ability of the lead to migrate far from the implantation site, which has rarely been reported. CITATION: Rosen R, Padhya T, Daniel J, Sharma A. Video-assisted thoracoscopic surgery retrieval of a migrated unilateral hypoglossal nerve stimulator sensor lead. J Clin Sleep Med. 2024;20(11):1851-1855.

Turicella otitidis hypoglossal nerve stimulator device associated infection.

71-year-old male with history of obstructive sleep apnea presented with persistent drainage from the surgical incision site over the recently implanted hypoglossal nerve stimulator. Wound cultures from device pocket identified the pathogen as Turicella otitidis. Clinical course included treatment with broad-spectrum intravenous antibiotics and device explantation. This case is the first known T. otitidis device associated infection.

Device-related outcomes following hypoglossal nerve stimulator implantation.

STUDY OBJECTIVES: Hypoglossal nerve stimulation (HGNS) has been widely used to treat obstructive sleep apnea in selected patients. Here we evaluate rates of revision and explant related to HGNS implantation and assess types of adverse events contributing to revision and explant. METHODS: Postmarket surveillance data for HGNS implanted between January 1, 2018 and March 31, 2022, were collected. Event rates and risk were calculated using the postmarket surveillance event counts and sales volume over the same period. Indications were categorized for analysis. Descriptive statistics were reported and freedom from explant or revision curves were grouped by year of implantation. RESULTS: Of the 20,881 HGNS implants assessed, rates of explant and revision within the first year were 0.723% and 1.542%, respectively. The most common indication for explant was infection (0.378%) and for revision was surgical correction (0.680%). Of the 5,820 devices with 3-year postimplantation data, the rate of explant was 2.680% and of revision was 3.557%. During this same interval, elective removal (1.478%) was the most common indication, and for revisions, surgical correction (1.134%). CONCLUSIONS: The efficacy of HGNS is comparable in the real world setting to published clinical trial data. Rates of explant and revision are low, supporting a satisfactory safety profile for this technology. CITATION: Moroco AE, Wei Z, Byrd I, et al. Device-related outcomes following hypoglossal nerve stimulator implantation. J Clin Sleep Med. 2024;20(9):1497-1503.

Impact of Hypoglossal Nerve Stimulation on Consumer Sleep Technology Metrics and Patient Symptoms.

OBJECTIVES: Obstructive sleep apnea (OSA) is usually assessed at discrete and infrequent timepoints. Wearable consumer sleep technologies (CST) may allow for more granular and longitudinal assessments of OSA therapy responses and OSA-related symptoms. METHODS: In this case series, we enrolled hypoglossal nerve stimulator (HGNS) patients who had an effective treatment response for an 8-week study using a wearable CST. Participants started with "HGNS-on," were randomized to turn off HGNS therapy during either week 4 or 5 ("HGNS-off"), followed by a return to therapy, "HGNS-resume." Participants completed validated symptom questionnaires assessing sleepiness, insomnia symptoms, functional status, and overall sleep health (Satisfaction, Alertness, Timing, Efficiency, and Duration, SATED) each week. CST metrics and survey scores were compared between HGNS treatment phases. Associations between CST metrics and survey scores were assessed. RESULTS: Seven participants with a total of 304 nights of CST data showed no statistically significant changes in total sleep time (TST), wake time after sleep onset, or sleep efficiency (SE) across the study periods. During HGNS-off, survey scores indicated significantly worsened OSA-related symptom scores. Two participants had significantly higher heart rate variability (HRV) during HGNS-off (by 3.3 and 6.3 ms) when compared to HGNS active therapy periods. Amongst CST metrics, SATED scores correlated with TST (r = 0.434, p < 0.0001), HRV (r = -0.486, p < 0.0001), and SE (r = 0.320, = 0.0014). In addition, FOSQ-10 scores correlated with average HR during sleep (r = -0.489, p < 0.001). CONCLUSION: A 1-week HGNS therapy withdrawal period impacted OSA-related sleep symptoms. Sleep-related metrics measured by a wearable CST correlated with symptom scores indicating potential value in the use of CSTs for longitudinal sleep-tracking in OSA patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3406-3411, 2024.

Treatment of Residual Palatal Collapse in Hypoglossal Nerve Stimulation Using a Palatal Device.

Hypoglossal nerve stimulation (HNS) has increasingly become an alternative therapy for obstructive sleep apnea patients with CPAP intolerance. Stimulation of the hypoglossal nerve during sleep enhances airway patency and alleviates collapse. Suboptimal responses to HNS often stem from insufficient palatal coupling and residual velar collapse. Combining palatal devices, such as Velumount®, with HNS represents a simple and cost-effective strategy to treat residual palatal collapse. Patients desiring conservative treatment for residual palatal obstruction under HNS may consider this combined approach. Laryngoscope, 134:3412-3414, 2024.

Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea in a Patient with Cerebral Palsy.

INTRODUCTION: Obstructive sleep apnea (OSA) is common amongst patients with cerebral palsy in part due to significant hypotonia. Hypoglossal nerve stimulation (HGNS) is a novel tool used to treat sleep apnea when there is failure with CPAP. To our knowledge, the literature has not discussed HGNS as a treatment option for severe OSA in patients with cerebral palsy. METHODS: Case report and literature review. RESULTS: A 28-year-old male with cerebral palsy, neuromuscular deformity, proximal junction kyphosis, and developmental delay presented with severe obstructive sleep apnea and was intolerant to CPAP and BiPAP. After HGNS implantation, a sleep study revealed improved ventilation and oxygenation at 2.4 V; AHI decreased from baseline of 112 to 12 events per hour with only mild intermittent snoring. The patient's family reported increased utilization compared with previous CPAP use. CONCLUSION: HGNS can be a safe and effective treatment modality for OSA in this patient population. Laryngoscope, 134:2478-2479, 2024.

Advances in the Use of Hypoglossal Nerve Stimulator in Adolescents With Down Syndrome and Persistent Obstructive Sleep Apnea-A Systematic Review.

INTRODUCTION: The Hypoglossal Nerve Stimulator (HNS) is a novel therapy that has been extensively studied in adults and more recently, it has been incorporated in children with Down Syndrome (DS) with persistent obstructive sleep apnea after adenotonsillectomy and trial of continuous positive airway pressure treatment. This systematic review article aims to examine the existing literature on HNS use in children to explore the benefits, efficacy, and parental experiences. METHODS: MEDLINE, Web of Science and EMBASE were searched to include all studies published up to March 2nd, 2023, on the topic of HNS use in pediatric population under 21 years old. RESULTS: A total of 179 studies were initially identified from which 10 articles were consistent with the inclusion criteria. Nine articles addressed outcomes after implantation of the HNS device in children with DS and 1 article explored the parental experiences. Findings were similar across studies where after implantation of HNS, there was marked improvement in polysomnographic outcomes and quality of life scores with high level of compliance. CONCLUSIONS: HNS holds promise as an effective treatment option for pediatric patients with DS and persistent OSA after AT and CPAP trials. It significantly improves sleep-disordered breathing, quality of life, and neurocognitive measures, leading to substantial and sustained benefits for these children. While the findings are encouraging, further research is needed to explore the potential of HNS in other pediatric populations without DS and to raise awareness among healthcare providers about this treatment option. Overall, HNS may offer significant long-term benefits for the overall well-being and health of pediatric patients with DS and persistent OSA.

Evaluating the Clinical Performance of a Novel, Precision Oral Appliance Therapy Medical Device Made Wholly From a Medical Grade Class VI Material for the Treatment of Obstructive Sleep Apnea.

Objective The objective of this study is to evaluate the clinical performance of a novel, precision, oral appliance therapy (OAT) medical device made entirely from a US Pharmacopeia (USP) medical grade class VI qualified material for the treatment of obstructive sleep apnea (OSA). Methods This was a multi-center, single-arm, chart-based, retrospective study of 91 patients diagnosed with OSA, treated utilizing a novel, precision, OAT medical device. Performance criteria were overall efficacy (reduction of OSA events to less than 10 per hour); efficacy for patients with severe OSA (reduction of OSA events to less than 20 per hour and a 50% improvement); and compliance (the rate of continuation of treatment after at least a one-year follow-up, or, conversely, the rate of discontinuation of treatment due to material-related adverse events or side effects after one year).  Results Eighty-nine percent of all subjects diagnosed with all levels of OSA severity were successfully treated to an apnea hypopnea index ("AHI") < 10 events per hour. Ninety-eight percent of subjects diagnosed with mild to moderate OSA were successfully treated to an AHI < 10. Eighty percent of subjects with severe OSA, without screening or excluding subjects for airway collapse profile, were successfully treated to an AHI < 20 with a 50% improvement in AHI. After a minimum one-year follow-up period, 96% of patients were confirmed to remain in active treatment. No subjects were reported to discontinue treatment due to adverse events or side effects. Conclusions This novel, precision OAT medical device made from the USP Class VI qualified material demonstrated efficacy and safety for the treatment of patients with OSA.

Hypoglossal Nerve Stimulation Therapy Outcomes in Apnea- Versus Hypopnea-Predominant Patients.

OBJECTIVES: The influence of apnea- and hypopnea-predominance on hypoglossal nerve stimulation therapy outcomes (HGNS) is still poorly defined. We assessed the significance of apnea- and hypopnea-predominance in HGNS outcomes. STUDY DESIGN: Case series with chart review. SETTING: Single-institution tertiary care center. METHODS: A total of 216 subjects were included, all of which had undergone drug-induced sleep endoscopy (DISE) and HGNS implantation. Demographic and polysomnographic data were collected. The 4% apnea-hypopnea criteria were used to calculate apnea-hypopnea index (AHI). Central apneas were omitted. Univariate logistic and linear regression were used to study the association between these data and apnea-predominance and hypopnea-predominance. Kruskal-Wallis rank sum test was used to compare medians between groups for DISE collapse patterns. RESULTS: Sixty-three patients were apnea-predominant, and 153 patients were hypopnea-predominant. These 2 groups were similar demographically (p > .20). There was no significant difference in HGNS outcomes between the groups assessed using Sher20 criteria at the 1-year mark using all-night, single-setting polysomnography or home sleep studies. Apnea index (AI)/AHI and reduction in AHI from preoperative to titration were significantly associated (p = .046). The median preoperative hypopnea index was significantly lower (p = .033) in subjects with no oropharyngeal collapse than patients with partial or complete oropharyngeal collapse. There were no significant relationships between AI/AHI and the different degrees of collapse at the velopharynx, oropharynx, tongue base, or epiglottis. CONCLUSIONS: In line with CPAP, tonsillectomy, and mandibular advancement therapy studies, we found there was largely no significant difference in DISE anatomy or in HGNS treatment outcomes between apnea- and hypopnea-predominant individuals.

Hypoglossal nerve stimulator on extraoral radiography and cone beam computed tomography scan: Case report.

BACKGROUND: The hypoglossal nerve stimulator (HNS) device has been employed in some patients with refractory or unsatisfactory outcomes to chronic obstructive sleep apnea management. The objective of this article is to increase recognition of the radiologic appearances of this device within the head and neck region, as seen on extraoral radiographic and cone beam computed tomography (CBCT) images. CLINICAL PRESENTATION: A 55-year-old man, refractory to a multitude of apneic medical therapies, underwent a series of preorthognathic radiologic studies. Notably, an implanted HNS lead and ribbon electrodes appeared as hyperdense structures on the panoramic radiograph, lateral cephalogram, and CBCT scan. CONCLUSION: This article provides various radiologic views of the primary components of an HNS. Clinicians should be able to recognize the presence of neurostimulator devices used for management of chronic sleep apnea within the radiologic field of view of examinations of the head and neck.

Novel Outcome Analysis Tool for Hypoglossal Nerve Stimulator Sensor Lead Function and Comparison by Incision Type (2 Versus 3).

OBJECTIVE: No reported outcome measures have been established to evaluate sensor lead function in the hypoglossal nerve stimulator (HNS). This study describes the development of novel functional outcome measures for intraoperative sensor electrode function and compares 2-incision and 3-incision outcomes for HNS. METHODS: A retrospective cohort study of 100 consecutive patients who underwent HNS between June 2019 and September 2021. Demographic information, intraoperative findings, and immediate postoperative outcomes were recorded. Structured parameters were developed to compare intraoperative waveforms with six outcome measures utilized: waveform syncing, waveform amplitude, sensory current leakage, shark-fin morphology, cardiac artifact, and overall impression. Two sleep surgeons and two sleep medicine specialists compared all waveforms in a blinded fashion and assigned scores on the Likert Scale. RESULTS: The cohort included 50 three-incision and 50 two-incision patients. Age, gender, average body mass index, comorbidity profiles, and sleep endoscopy findings did not significantly differ between the two groups. No major complications occurred. The interclass-correlation-coefficient was greater than 0.7 for all comparisons (good to very good interrater reliability). There was no difference in waveform amplitude, cardiac artifact, sensory current leakage, or shark-fin morphology between the two groups. Waveform syncing and overall impression were statistically better in the 2-incision cohort. CONCLUSIONS: This study is the first to define a structured method of HNS sensor electrode outcome measurement and showed consistent measures by surgeons and sleep medicine specialists. This article supports the transition to the 2-incision technique among surgeons for placement of the sensor lead. Consideration should be given to utilizing this novel tool in the clinical/research setting and validating these measures moving forward. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:423-430, 2023.

Parental experience of hypoglossal nerve stimulator implantation in adolescents with Down Syndrome and obstructive sleep apnea.

PURPOSE: The purpose of this study is to explore the experience of parents in deciding whether to participate in a clinical trial of the insertion of the Hypoglossal Nerve Stimulator (HNS) to treat their adolescent with Down Syndrome (DS) and Obstructive Sleep Apnea (OSA). DESIGN AND METHODS: A qualitative descriptive design with interviews was used to gather parental experiences from those who consented to HNS for their adolescent with DS and OSA. Interviews were conducted, audiotaped, and transcribed. Basic content analysis was followed to interpret the data. Using a process of data debriefing/engagement, codes were generated, and field/reflective notes were used to assure trustworthiness of the data. RESULTS: Parents, 13 mothers/2 fathers, participated. Three themes were identified: Parents experience desperation about acceptance of standard of care for their adolescent with DS and OSA. This desperation led parents to seek information/insights from social media and they came to rely on those sites to explore options, ultimately leading them to HNS clinical trial. Finally, parents had a desire to share experience with HNS implantation. CONCLUSIONS: Parents described being desperate at acceptance of standards of care for OSA. They shifted reliance on experts and parents by searching social media pages to explore options for treatment of OSA. Parents wished to share experiences with the HNS implantation. PRACTICE IMPLICATIONS: Nurses play a role in preparing for the HNS by instructing/educating parents. Nurses can identify supportive social media sites for parents during the HNS decision and suggest ways to measure outcomes of HNS.

Association of hypoglossal nerve stimulator response with machine learning identified negative effort dependence patterns.

BACKGROUND: Hypoglossal nerve stimulator (HGNS) is a therapeutic option for moderate to severe obstructive sleep apnea (OSA). Improved patient selection criteria are needed to target those most likely to benefit. We hypothesized that the pattern of negative effort dependence (NED) on inspiratory flow limited waveforms recorded during sleep, which has been correlated with the site of upper airway collapse, would contribute to the prediction of HGNS outcome. We developed a machine learning (ML) algorithm to identify NED patterns in pre-treatment sleep studies. We hypothesized that the predominant NED pattern would differ between HGNS responders and non-responders. METHODS: An ML algorithm to identify NED patterns on the inspiratory portion of the nasal pressure waveform was derived from 5 development set polysomnograms. The algorithm was applied to pre-treatment sleep studies of subjects who underwent HGNS implantation to determine the percentage of each NED pattern. HGNS response was defined by STAR trial criteria for success (apnea-hypopnea index (AHI) reduced by > 50% and < 20/h) as well as by a change in AHI and oxygenation metrics. The predominant NED pattern in HGNS responders and non-responders was determined. Other variables including demographics and oxygenation metrics were also assessed between responders and non-responders. RESULTS: Of 45 subjects, 4 were excluded due to technically inadequate polysomnograms. In the remaining 41 subjects, ML accurately distinguished three NED patterns (minimal, non-discontinuous, and discontinuous). The percentage of NED minimal breaths was significantly greater in responders compared with non-responders (p = 0.01) when the response was defined based on STAR trial criteria, change in AHI, and oxygenation metrics. CONCLUSION: ML can accurately identify NED patterns in pre-treatment sleep studies. There was a statistically significant difference in the predominant NED pattern between HGNS responders and non-responders with a greater NED minimal pattern in responders. Prospective studies incorporating NED patterns into predictive modeling of factors determining HGNS outcomes are needed.

Interference With Implanted Upper Airway Stimulation Device by Phones With Magnet Technology.

Newer iPhone models with MagSafe magnetic technology can cause electromagnetic interference with the Inspire upper airway stimulator device (a surgical implant for the treatment of obstructive sleep apnea). Laryngoscope, 132:2513-2515, 2022.

Hypoglossal Nerve Stimulator Explantation: A Case Series.

Hypoglossal nerve stimulation (HGNS) has emerged as a successful surgical treatment strategy for moderate to severe obstructive sleep apnea in patients failing first-line positive airway pressure therapy. HGNS explantation due to adverse events such as pain and infection is rare and has yet to be well described. Here, our correspondence describes the first case series of patients who have undergone explantation of the Inspire HGNS system. Five patients were identified who underwent HGNS explantation. Three patients underwent explantation due to magnetic resonance imaging (MRI) incompatibility. One patient underwent explantation due to poor cosmesis. One patient underwent explantation due to surgical site infection. Average operative explant time was 163 minutes. MRI incompatibility, poor cosmesis, and device-related infection are reasons for HGNS explantation. Future need for MRI or chest wall surgery should be considered in patients being evaluated for HGNS implants.