Advanced titration to treat a floppy epiglottis in selective upper airway stimulation

Treatment of a floppy epiglottis with upper airway stimulation therapy

PURPOSE

To evaluate the efficacy of upper airway stimulation therapy in patients with a floppy epiglottis who have experienced continuous positive airway pressure failure or intolerance.

METHODS

A retrospective single-center cohort study was conducted. Patients who received an Inspire Upper Airway Stimulation system and had a 1-year follow-up were included. Baseline and one-year in-laboratory polysomnography examinations were performed. Patient characteristics, Epworth Sleepiness Scale scores and upper airway stimulation device settings were collected.

RESULTS

A total of 75 patients were included, of whom 10 had a floppy epiglottis. Patients with a floppy epiglottis had a significant therapeutic response to upper airway stimulation therapy, similar to patients without a floppy epiglottis. According to the Sher's success criteria, 90% of patients with a floppy epiglottis and 68% of patients without a floppy epiglottis were responders to therapy (p = 0.149). In the floppy epiglottis group, the apnea-hypopnea index decreased from 35.1 ± 5.5 events/hour to 11.2 ± 11.3 events/hour (95% CI (15.0, 32.9), p < 0.001), similarly in the non-floppy epiglottis group, the decline was from 36.4 ± 8.3 events/hour to 14.4 ± 9.5 events/hour (95% CI (18.6, 25.2), p < 0.001, between groups p = 0.659). Comparable reductions were observed for the other respiratory parameters.

CONCLUSION

Treatment of patients with obstructive sleep apnea and a floppy epiglottis can be challenging. Continuous positive airway pressure may aggravate the epiglottis collapse. Upper airway stimulation therapy can be considered an effective alternative treatment option for patients with a floppy epiglottis who have encountered either continuous positive airway pressure failure or intolerance.

An Overview of Systematic Reviews on the Surgical Management of Obstructive Sleep Apnoea

Background

Obstructive Sleep Apnoea (OSA) is a common sleep disorder marked by partial or total obstruction of the upper airway while a person is asleep leading to breathing difficulty, reduced oxygenation and frequent awakenings. This condition affects the general health significantly compromising quality of life. The objective of this overview  is to thoroughly assess the systematic reviews on current surgical therapies for the management of OSA in terms of patient outcomes.

Methods

A thorough literature search was performed from inception till 31st December 2022 using PubMed, and Cochrane databases. Studies evaluating the effectiveness and safety of different surgical techniques for the management of OSA were considered. The quality of articles was assessed using AMSTAR (A MeaSurement Tool to Assess systematic Reviews) and Glenny et al. checklist.

Results

Out of eighteen studies, only seven studies met the inclusion and exclusion criteria. Results showed that the majority of studies were in the pediatric age group except one systematic  review which assessed the adult age group.

Conclusion

None of the published articles had compared all surgical procedures based on the standard evaluating procedure nor followed all reporting guidelines in the primary studies. For better implementation, further multi center studies are warranted with unique reporting criteria and guidelines about pre- as well as post-operative phases. Future research should concentrate on contrasting strategies, combination therapies, and evaluating long-term effects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12663-023-02051-x.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Surgical Treatment Options for Epiglottic Collapse in Adult Obstructive Sleep Apnoea: A Systematic Review

The critical role of epiglottis in airway narrowing contributing to obstructive sleep apnoea (OSA) and continuous positive airway pressure (CPAP) intolerance has recently been revealed. This systematic review was conducted to evaluate available surgical treatment options for epiglottic collapse in adult patients with OSA. The Pubmed and Scopus databases were searched for relevant articles up to and including March 2022 and sixteen studies were selected. Overall, six different surgical techniques were described, including partial epiglottectomy, epiglottis stiffening operation, glossoepiglottopexy, supraglottoplasty, transoral robotic surgery, maxillomandibular advancement and hypoglossal nerve stimulation. All surgical methods were reported to be safe and effective in managing selected OSA patients with airway narrowing at the level of epiglottis. The surgical management of epiglottic collapse can improve OSA severity or even cure OSA, but can also improve CPAP compliance. The selection of the appropriate surgical technique should be part of an individualised, patient-specific therapeutic approach. However, there are not enough data to make definitive conclusions and additional high-quality studies are required.

Bilateral vs Unilateral Hypoglossal Nerve Stimulation in Patients With Obstructive Sleep Apnea

Objective

Unilateral hypoglossal nerve stimulation (uniHNS) is an effective treatment for obstructive sleep apnea. Bilateral hypoglossal nerve stimulation (biHNS) is a novel therapeutic option and a different approach to hypoglossal nerve stimulation. The aim of this study was to analyze the clinical outcome of the first 10 biHNS cases vs the first 10 uniHNS cases ever implanted.

Study Design

Prospective data analysis.

Setting

International multicenter comparative clinical trial.

Methods

The first 10 patients in 2020 who received a biHNS device (Genio System; Nyxoah) and the first 10 patients in 2014 who received a uniHNS system (Inspire II; Inspire Medical Systems) were included. Treatment outcome was evaluated at 3 months after surgery. Data collection included demographics, apnea hypopnea index (AHI), oxygen saturation and desaturation index, Epworth Sleepiness Scale, and adverse events.

Results

The mean ± SD age was 52.1 ± 9.6 years (biHNS) and 58.3 ± 8.6 years (uniHNS). The mean body mass index was 26.4 ± 5.6 kg/m² (biHNS) and 26.2 ± 2.2 kg/m² (uniHNS). The mean preimplantation AHI (biHNS, 39.9 ± 14.8/h; uniHNS, 32.2 ± 11.0/h) decreased in both groups after 3 months (biHNS, 19.2 ± 14.0/h, P = .008; uniHNS, 13.1 ± 16.8/h, P = .037) with no significant difference between groups (P = .720). The mean preimplantation Epworth Sleepiness Scale (biHNS, 11.8 ± 6.2; uniHNS, 11.1 ± 4.9) decreased as well after 3 months (biHNS, 9.4 ± 6.3; uniHNS, 6.0 ± 5.0).

Conclusion

Preliminary postmarket data suggest that biHNS may be as safe and effective as uniHNS. Long-term follow-up in a larger sample size is required to assess the stability of biHNS.

Ultrasound Shear Wave Elastography of the Tongue during Selective Hypoglossal Nerve Stimulation in Patients with Obstructive Sleep Apnea Syndrome

Currently, there is no established technique to directly measure extrinsic tongue muscle activation during selective hypoglossal stimulation therapy (sHNS) in patients with obstructive sleep apnea syndrome (OSAS) in a simple, non-invasive clinical setting. Ultrasound shear-wave elastography (US-SWE) enables quantitative measurement of tissue stiffness. We investigated whether US-SWE is able to detect changes in muscle stiffness of the tongue during sHNS. Patients with OSAS treated with sHNS were prospectively enrolled. A standardized US-SWE protocol was used to selectively measure tissue stiffness of the geniohyoid muscle (GH) and genioglossus (GG) muscles on the side of stimulator implantation (sGH, sGG) and on the contralateral side (nGH, nGG) without and with sHNS. Eighteen patients were included (median age = 62 years, interquartile range: 56-65, 83.3% male). Median shear-wave velocity (SWV) increased during contraction with each patient's clinically prescribed therapeutic regimen in the sGH (+19%, p = 0.020) and sGG (+81%, p < 0.001) and decreased during contraction in the nGH (-8%, p = 0.107) and nGG (-8%, p = 0.396). Differences in SWV during contraction were significant only on the side of stimulation (sGG +81%, sGH +19%). SWE measurements had excellent reliability as reflected by a Cronbach α value ≥0.9 for all target muscles pre- and post-contraction and an item-total correlation ≥0.5. US-SWE allows reliable measurement of SWV as an indicator of muscle stiffness of extrinsic tongue muscles. This non-invasive method provides new possibilities to distinguish and characterize responders from non-responders in hypoglossal stimulation therapy. Compared with the regular visual assessment of tongue movement, US-SWE of individual muscle groups provides a new non-invasive imaging tool in patients with OSAS.

Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions and research gaps. Proceedings of the 2019 International Sleep Surgery Society Research Forum

Hypoglossal nerve stimulation (HGNS) has evolved as a novel and effective therapy for patients with moderate-to-severe obstructive sleep apnea (OSA). Despite positive published outcomes of HGNS, there exist uncertainties regarding proper patient selection, surgical technique, and the reporting of outcomes and individual factors that impact therapy effectiveness. According to current guidelines, this therapy is indicated for select patients, and recommendations are based on the Stimulation Therapy for Apnea Reduction (STAR) trial. Ongoing research and physician experiences continuously improve methods to optimize the therapy. An understanding of the way in which airway anatomy, OSA phenotypes, individual health status, psychological conditions and comorbid sleep disorders influence the effectiveness of HGNS is essential to improve outcomes and expand therapy indications. This manuscript presents discussions on current evidence, future directions, and research gaps for HGNS therapy from the 10th International Surgical Sleep Society expert research panel.

Effect of Electrode Configuration and Impulse Strength on Airway Patency in Neurostimulation for Obstructive Sleep Apnea

OBJECTIVES/HYPOTHESIS

Hypoglossal nerve stimulation (HNS) has gained increasing interest for the treatment of patients with obstructive sleep apnea (OSA). Drug-induced sleep endoscopy (DISE) can both exclude improper airway collapse patterns and visualize airway changes under stimulation. Stimulation outcome effects depend on the impulse voltage and electric field resulting from the electrode configuration of the implanted device. The effects of various combinations of voltage and electric field on DISE airway patterns in contrast to awake endoscopy are unknown.

STUDY DESIGN

Cohort study.

METHODS

During therapy adjustment about 6 months after implantation, patients underwent a DISE and awake endoscopy with 100% and 125% of functional voltage in three typical electrode configurations (+ - +, o - o, - - -). All videos were analyzed by two separate persons for the opening of the airway at velum, tongue base, and epiglottis level.

RESULTS

Thirty patients showed typical demographic data. The opening effects were visible in all patients, but there were changes between different electrode configurations. Several demographic or therapeutic aspects such as obesity, OSA severity, or prior soft palate surgery were associated with changes arising from different electrode configurations, but none resulted in a consistently better airway opening.

CONCLUSIONS

In patients with poor results during the therapy adjustment, electric configuration changes can improve airway patency-an independent variable from increasing voltage. As these effects can only be seen in awake endoscopy or DISE, both endoscopies with live stimulation may be considered in cases with insufficient improvement in apnea-hypopnea index after initiation of HNS therapy.

LEVEL OF EVIDENCE

Prospective case series; level 4. Laryngoscope, 131:2148-2153, 2021.

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.

Bilateral hypoglossal nerve stimulation for treatment of adult obstructive sleep apnoea

BACKGROUND AND AIM

Hypoglossal nerve stimulation (HNS) decreases obstructive sleep apnoea (OSA) severity via genioglossus muscle activation and decreased upper airway collapsibility. This study assessed the safety and effectiveness at 6 months post-implantation of a novel device delivering bilateral HNS via a small implanted electrode activated by a unit worn externally, to treat OSA: the Genio™ system.

METHODS

This prospective, open-label, non-randomised, single-arm treatment study was conducted at eight centres in three countries (Australia, France and the UK). Primary outcomes were incidence of device-related serious adverse events and change in the apnoea-hypopnoea index (AHI). The secondary outcome was the change in the 4% oxygen desaturation index (ODI). Additional outcomes included measures of sleepiness, quality of life, snoring and device use. This trial was registered with ClinicalTrials.gov, number NCT03048604.

RESULTS

22 out of 27 implanted participants (63% male, aged 55.9±12.0 years, body mass index (BMI) 27.4±3.0 kg·m^-2) completed the protocol. At 6 months BMI was unchanged (p=0.85); AHI decreased from 23.7±12.2 to 12.9±10.1 events·h^-1, a mean change of 10.8 events·h^-1 (p<0.001); and ODI decreased from 19.1±11.2 to 9.8±6.9 events·h^-1, a mean change of 9.3 events·h^-1 (p<0.001). Daytime sleepiness (Epworth Sleepiness Scale; p=0.01) and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire-10; p=0.02) both improved significantly. The number of bed partners reporting loud, very intense snoring, or leaving the bedroom due to participant snoring decreased from 96% to 35%. 91% of participants reported device use >5 days per week, and 77% reported use for >5 h per night. No device-related serious adverse events occurred during the 6-month post-implantation period.

CONCLUSIONS

Bilateral HNS using the Genio™ system reduces OSA severity and improves quality of life without device-related complications. The results are comparable with previously published HNS systems despite minimal implanted components and a simple stimulation algorithm.

Addressing the Tone and Synchrony Issue During Sleep: Pacing the Hypoglossal Nerve

Upper airway stimulation is a novel therapy for patients suffering from obstructive sleep apnea who are incompliant toward continuous positive airway pressure therapy. Evidence supporting the effectiveness of this therapy with regard to the treatment of disordered breathing, subjective daytime impairment, and its effect on sleep characteristics has increased. Information on the subjective sensation of the stimulation of the hypoglossal nerve could be gathered as more patients are implanted and knowledge of different aspects of the therapy is increasing. Comparisons between upper airway stimulation therapy and other surgical treatment options have been conducted. The surgical technique could be further optimized.

Neurostimulation Treatment of OSA

Over the past 30 years, hypoglossal nerve stimulation has moved through a development pathway to become a viable treatment modality for patients with OSA. Initial pilot studies in animals and humans laid the conceptual foundation for this approach, leading to the development of fully implantable stimulating systems for therapeutic purposes. These devices were then shown to be both safe and efficacious in feasibility studies. One such closed-loop stimulating device was found to be effective in treating a limited spectrum of apneic patients and is currently approved by the US Food and Drug Administration for this purpose. Another open-loop stimulating system is currently being rigorously tested in a pivotal trial. Collectively, clinical trials of hypoglossal nerve stimulating systems have yielded important insights that can help optimize therapeutic responses to hypoglossal nerve stimulation. These insights include specific patient selection criteria and methods for delivering stimulation to specific portions of the hypoglossal nerve and/or genioglossus muscle. New approaches for activating efferent and afferent motor pathways are currently in early-stage laboratory development and hold some long-term promise as a novel therapy.

Improving surgical results in complex nerve anatomy during implantation of selective upper airway stimulation

The following report presents a case of two late embedded hypoglossus branches during implantation of an upper airway stimulation device that caused a mixed activation of the tongue when included in the stimulation cuff. In the end, correct cuff placement could be achieved by careful examination of the hypoglossal nerve anatomy, precise nerve dissection, tongue motion analysis and intraoperative nerve monitoring.

Development of a Clinical Pathway and Technical Aspects of Upper Airway Stimulation Therapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disease with high morbidity and related mortality. Narrowing and collapse of the pharyngeal airway during sleep characterize the disease, resulting in a decrease (hypopnea) or a complete cessation (apnea) of oronasal airflow. Upper airway stimulation (UAS), using electrical neurostimulation of the hypoglossal nerve (n. XII) synchronized with ventilation, is a novel, evolving treatment option. UAS was found to be an effective treatment in CPAP-intolerant patients. The treatment success is partly due to the strict selection of the patients, based on previous findings. Furthermore, post-operative follow-up is needed in order to maintain or improve treatment outcome. Therefore, a clinical pathway, which provides structure and standardization, is crucial. In this paper, the aim is to discuss the technical aspects of UAS therapy and to describe a clinical pathway to organize the care process of UAS for OSA in a structured and standardized way.