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.

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.

Mandibular advancement reduces pharyngeal collapsibility by enlarging the airway rather than affecting velopharyngeal compliance

Mandibular advancement devices (MADs) are frequently prescribed for obstructive sleep apnea (OSA) patients, but approximately one third of patients experience no therapeutic benefit. Understanding the mechanisms by which MADs prevent pharyngeal collapse may help optimize MAD therapy. This study quantified the relative contributions of changes in airspace cross-sectional area (CSA) versus changes in velopharyngeal compliance in determining MAD efficacy. Sixteen patients with moderate to severe OSA (mean apnea-hypopnea index of 32 ± 15 events/h) underwent measurements of the velopharyngeal closing pressure (PCLOSE ) during drug induced sedated endoscopy (DISE) via stepwise reductions in nasal mask pressure and recording of the intraluminal pressure with a catheter. Airspace CSA was estimated from video endoscopy. Pharyngeal compliance was defined as the slope of the area-pressure relationship of the velopharyngeal airspace. MAD therapy reduced PCLOSE from a median of 0.5 cmH2 O pre-advancement to a median of -2.6 cmH2 O post-advancement (p = 0.0009), increased the minimal CSA at the velopharynx by approximately 20 mm2 (p = 0.0067), but did not have a statistically significant effect on velopharyngeal compliance (p = 0.23). PCLOSE had a strong correlation with CSA but did not correlate with velopharyngeal compliance. Our results suggest that MADs reduce velopharyngeal collapsibility by increasing airway size as opposed to affecting velopharyngeal compliance. This contradicts the speculation of previous literature that the effectiveness of MADs is partially due to a reduction in velopharyngeal compliance resulting from stretching of the soft palate. These findings suggest that quantification of velopharyngeal CSA pre- and post-MAD advancement has potential as a biomarker to predict the success of MAD therapy.

Anatomical determinants of upper airway collapsibility in obstructive sleep apnea: A systematic review and meta-analysis

Upper airway (UA) collapsibility is one of the key factors that determine the severity of obstructive sleep apnea (OSA). Interventions for OSA are aimed at reducing UA collapsibility, but selecting the optimal alternative intervention for patients who fail CPAP is challenging because currently no validated method predicts how anatomical changes affect UA collapsibility. The gold standard objective measure of UA collapsibility is the pharyngeal critical pressure (P_crit). A systematic literature review and meta-analysis were performed to identify the anatomical factors with the strongest correlation with P_crit. A search using the PRISMA methodology was performed on PubMed for English language scientific papers that correlated P_crit to anatomic variables and OSA severity as measured by the apnea-hypopnea index (AHI). A total of 29 papers that matched eligibility criteria were included in the quantitative synthesis. The meta-analysis suggested that AHI has only a moderate correlation with P_crit (estimated Pearson correlation coefficient r = 0.46). The meta-analysis identified four key anatomical variables associated with UA collapsibility, namely hyoid position (r = 0.53), tongue volume (r = 0.51), pharyngeal length (r = 0.50), and waist circumference (r = 0.49). In the future, biomechanical models that quantify the relative importance of these anatomical factors in determining UA collapsibility may help identify the optimal intervention for each patient. Many anatomical and structural factors such as airspace cross-sectional areas, epiglottic collapse, and palatal prolapse have inadequate data and require further research.

Effect of tube length on the buckling pressure of collapsible tubes

BACKGROUND

The higher incidence of obstructive sleep apnea (OSA) in men than in women has been attributed to the upper airway being longer in men. The Starling resistor is the paradigm biomechanical model of upper airway collapse in OSA where a collapsible tube (representing the pharynx) is located between two rigid tubes (representing the nasal cavity and trachea). While the Starling resistor has been extensively studied due to its relevance to many physiological phenomena, the effect of tube length on tube collapsibility has not been quantified yet.

METHODS

Finite element analysis of a 3-dimensional collapsible tube subjected to a transmural pressure was performed in ANSYS Workbench. The numerical methods were validated with in vitro experiments in a silicone tube whose modulus of elasticity (361 ± 28 kPa) and dimensions (length = 100 mm, diameter = 22.2 mm, and wall thickness = 1.59 mm) were selected so that tube compliance was similar to pharyngeal compliance in humans during sleep. The buckling pressure (transmural pressure at which the tube collapses) was quantified in tubes of three different diameters (10 mm, 16 mm, and 22.2 mm) and ten length-to-diameter ratios (L/D = 4 to 13), while keeping the wall-thickness-to-radius ratio constant at 0.143.

RESULTS

The absolute value of the buckling pressure decreased from 4.7 to 3.3 cmH₂O (461-324 Pa) when L/D increased from 4 to 13. The buckling pressure was nearly independent from tube length for L/D >10.

CONCLUSIONS

Our finding that longer tubes are more collapsible than shorter tubes is consistent with the higher incidence of obstructive sleep apnea in males than females.

Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulation Outcomes: A Multicenter Cohort Study

OBJECTIVES/HYPOTHESIS

To determine the association between findings of blinded reviews of preoperative drug-induced sleep endoscopy (DISE) and outcomes of hypoglossal nerve stimulation (HNS) for obstructive sleep apnea (OSA).

STUDY DESIGN

Cohort study.

METHODS

A retrospective, multicenter cohort study of 343 adults who underwent treatment of OSA with HNS from 10 academic medical centers was performed. Preoperative DISE videos were scored by four blinded reviewers using the VOTE Classification and evaluation of a possible primary structure contributing to airway obstruction. Consensus DISE findings were examined for an association with surgical outcomes based on therapy titration polysomnogram (tPSG). Treatment response was defined by a decrease of ≥50% in the apnea-hypopnea index (AHI) to <15 events/hour.

RESULTS

Study participants (76% male, 60.4 ± 11.0 years old) had a body mass index of 29.2 ± 3.6 kg/m² . AHI decreased (35.6 ± 15.2 to 11.0 ± 14.1 events/hour; P < .001) on the tPSG, with a 72.6% response rate. Complete palate obstruction (vs. none) was associated with the greatest difference in AHI improvement (-26.8 ± 14.9 vs. -19.2 ± 12.8, P = .02). Complete (vs. partial/none) tongue-related obstruction was associated with increased odds of treatment response (78% vs. 68%, P = .043). Complete (vs. partial/none) oropharyngeal lateral wall-related obstruction was associated with lower odds of surgical response (58% vs. 74%, P = .042).

CONCLUSIONS

The DISE finding of primary tongue contribution to airway obstruction was associated with better outcomes, whereas the opposite was true for the oropharyngeal lateral walls. This study suggests that the role for DISE in counseling candidates for HNS extends beyond solely for excluding complete concentric collapse related to the velum.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:1676-1682, 2021.

A New Metric for Precision Medicine: PAP and Hypoglossal Neurostimulation

CITATION

Jacobowitz O, Woodson BT. A new metric for precision medicine: PAP and hypoglossal neurostimulation. J Clin Sleep Med. 2019;15(8):1079-1080.

Airflow limitation in a collapsible model of the human pharynx: physical mechanisms studied with fluid-structure interaction simulations and experiments

The classical Starling Resistor model has been the paradigm of airway collapse in obstructive sleep apnea (OSA) for the last 30 years. Its theoretical framework is grounded on the wave-speed flow limitation (WSFL) theory. Recent observations of negative effort dependence in OSA patients violate the predictions of the WSFL theory. Fluid-structure interaction (FSI) simulations are emerging as a technique to quantify how the biomechanical properties of the upper airway determine the shape of the pressure-flow curve. This study aimed to test two predictions of the WSFL theory, namely (1) the pressure profile upstream from the choke point becomes independent of downstream pressure during flow limitation and (2) the maximum flowrate in a collapsible tube is V I max = A 3 / 2 ( ρ d A / d P ) - 1 / 2 , where ρ is air density and A and P are the cross-sectional area and pressure at the choke point respectively. FSI simulations were performed in a model of the human upper airway with a collapsible pharynx whose wall thickness varied from 2 to 8 mm and modulus of elasticity ranged from 2 to 30 kPa. Experimental measurements in an airway replica with a silicone pharynx validated the numerical methods. Good agreement was found between our FSI simulations and the WSFL theory. Other key findings include: (1) the pressure-flow curve is independent of breathing effort (downstream pressure vs. time profile); (2) the shape of the pressure-flow curve reflects the airway biomechanical properties, so that V I max is a surrogate measure of pharyngeal compliance.

Palatal anatomy for sleep apnea surgery

The goal of this review is to advance the understanding of the muscular and soft tissue palatal anatomy as it relates to palatal surgery for sleep apnea and the phenotypic variations that generate the shape and collapsibility of the retropalatal airway. Anatomically, the soft palate has both a proximal and distal segments separated by the palatal genu. The proximal palatal segment has a variable angle from the hard palate (ie, alpha angle) determined by the position and length of the levator veli palatini muscle. The palatopharyngeus muscle (PP) is a major defining element of the palate and lateral pharyngeal wall and forms the medial wall of the lateral palatal space. It is composed of two divisions: the longitudinal palatopharyngeus fasciculi which acts to elevate the pharynx and depress the soft palate and the transverse palatopharyngeus fascicle (Passavant's ridge) which function is a nasopharyngeal sphincter. The lateral palatal space incorporates the supra-tonsilar fat, and is bounded by muscles that determine the structure of the palate and associated lateral pharyngeal walls. Understanding of palatal muscles and pharyngeal airway phenotypes provides insight into the steps and mechanisms of pharyngoplasty procedures.

Level of Evidence

N/A.

Drug-Induced Sleep Endoscopy and Surgical Outcomes: A Multicenter Cohort Study

OBJECTIVE

To evaluate the association between findings of blinded reviews of preoperative drug-induced sleep endoscopy (DISE) examinations using the VOTE Classification and obstructive sleep apnea (OSA) surgical outcomes in a large multicenter, international cohort.

METHODS

Retrospective, multi-center cohort study of adults without tonsillar hypertrophy who underwent pharyngeal surgery for OSA. The study included only participants without enlarged tonsils. Four independent reviewers performed blinded review of preoperative DISE videos using the VOTE Classification system and scoring of a primary structure contributing to airway obstruction. DISE findings were examined for an association with surgical outcomes with univariate analyses and multiple regression.

RESULTS

Two hundred seventy-five study participants were included from 14 centers. Mean age was 51.4 ± 11.8 years, and body mass index was 30.1 ± 5.2 kg/m² . There was moderate interrater reliability (kappa = 0.40-0.60) for DISE findings. Oropharyngeal lateral wall-related obstruction was associated with poorer surgical outcomes (adjusted odds ratio (AOR) 0.51; 95% CI 0.27, 0.93). Complete tongue-related obstruction was associated with a lower odds of surgical response in moderate to severe OSA (AOR 0.52; 95% CI 0.28, 0.98), with findings that were similar but not statistically significant in other analyses. Surgical outcomes were not clearly associated with the degree and configuration of velum-related obstruction or the degree of epiglottis-related obstruction. Surgical response was associated with tonsil size and body mass index (inversely).

CONCLUSION

DISE findings concerning the oropharyngeal lateral walls and tongue may be the most important findings of this evaluation technique.

LEVEL OF EVIDENCE

2B Laryngoscope, 129:761-770, 2019.

Upper Airway Stimulation for Obstructive Sleep Apnea: 5-Year Outcomes

Objective To present 5-year outcomes from a prospective cohort of patients with obstructive sleep apnea (OSA) who were treated with upper airway stimulation (UAS) via a unilateral hypoglossal nerve implant. Study Design A multicenter prospective cohort study. Setting Industry-supported multicenter academic and clinical trial. Methods From a cohort of 126 patients, 97 completed protocol, and 71 consented to a voluntary polysomnogram. Those having continuous positive airway pressure failure with moderate to severe OSA, body mass index <32 kg/m², and no unfavorable collapse on drug-induced sleep endoscopy were enrolled in a phase 3 trial. Prospective outcomes included apnea-hypopnea index (AHI), oxygen desaturation index, and adverse events, as well as measures of sleepiness, quality of life, and snoring. Results Patients who did and did not complete the protocol differed in baseline AHI, oxygen desaturation index, and Functional Outcomes of Sleep Questionnaire scores but not in any other demographics or treatment response measures. Improvement in sleepiness (Epworth Sleepiness Scale) and quality of life was observed, with normalization of scores increasing from 33% to 78% and 15% to 67%, respectively. AHI response rate (AHI <20 events per hour and >50% reduction) was 75% (n = 71). When a last observation carried forward analysis was applied, the responder rate was 63% at 5 years. Serious device-related events all related to lead/device adjustments were reported in 6% of patients. Conclusions Improvements in sleepiness, quality of life, and respiratory outcomes are observed with 5 years of UAS. Serious adverse events are uncommon. UAS is a nonanatomic surgical treatment with long-term benefit for individuals with moderate to severe OSA who have failed nasal continuous positive airway pressure.

Application of drug-induced sleep endoscopy in patients treated with upper airway stimulation therapy

Objective

To determine the level of agreement among experienced operators of candidacy for upper airway stimulation (UAS) based on evaluation of drug-induced sleep endoscopy (DISE).

Methods

The trial was designed as a single-blinded cross-sectional study. Four otolaryngologists with extensive DISE experience were given 63 video clips from the STAR trial video library. These videos were graded using the VOTE classification. Percentage agreement and Cohen’s κ (for inter-rater reliability) were calculated between pairs of reviewers, assessing palatal complete concentric collapse (CCC) and determining UAS eligibility. Subjects were also grouped based on collapse severity for each reviewer.

Results

The reviewers had excellent (approximately 90%) agreement on findings at the level of the soft palate and tongue base. The inter-rater reliability for palatal CCC ranged from moderate to substantial. The agreement on determining the criteria for UAS implantation ranged from poor to moderate. All 4 upper airway structures as classified by the criteria of the VOTE were graded by all the reviewers as contributing to obstruction in a majority of subjects who were performed via application of DISE.

Conclusion

Application of DISE remains a subjective examination, even among those experienced operators, therefore more studies need to be performed for evaluation of improvement in inter-rater reliability after implantation of training videos.

Radiofrequency ablation of the lateral palatal space for snoring

Objective

Pilot study to examine the effect of radiofrequency ablation (RFA) of the lateral palatal fat pad in patients with socially-disruptive snoring.

Method

Snoring outcomes and complications were compared between a group of patients with treated with RFA ablation of the lateral soft palate fat pad with or without inferior turbinate reduction (8 patients) and another group undergoing inferior turbinate reduction alone (12 patients).

Results

Snoring loudness and bothersomeness improved in the palate but not inferior turbinate group. Pain was mild and no major complications were observed.

Conclusion

The study supports RFA ablation of the lateral palatal space as a potential low morbidity procedure for snoring.

Updates of operative techniques for upper airway stimulation

Selective upper airway stimulation has been established as an additional treatment for obstructive sleep apnea (OSA). Essential for the treatment is the precise placement of the cuff electrode for select branches of the hypoglossal nerve, which innervate the protrusors and stiffeners of the tongue. A direct approach to the distal hypoglossal nerve has been established to achieve this goal. For surgeons, detailed knowledge of this anatomy is vital. Another decisive step is the placement of the sensing lead between the intercostal muscles. Also, the complexity of follow-up care postoperatively should be kept in mind. The aim of this article is to provide the latest knowledge on the neuroanatomy of the hypoglossal nerve and to give surgeons a step-by-step guide on the current operative technique. Laryngoscope, 126:S12-S16, 2016.

Updated Hypopharyngeal Surgery for Sleep Apnea

The failure of traditional upper airway surgery such as uvulopalatopharyngoplasty has been attributed to lower airway obstruction related to base of tongue collapse. Multiple procedures, including glossectomy, tongue base radiofrequency, genioglossus advancement, and tongue suspension techniques, have been advocated to improve success rates. No consensus exists on which subsets of patients are best treated by individual approaches and direct comparative data are lacking. The selection of procedures must be based on individual patient needs and the relative potential benefits and risks.

OSA treatment history in an upper airway stimulation trial cohort

Objectives

Analyze the obstructive sleep apnea (OSA) treatment history in a group of participants who enrolled in a hypoglossal nerve stimulation trial.

Methods

Moderate-severe OSA patients with difficulty adhering to CPAP presented for enrollment in a multicenter trial. Self-reported history on prior OSA medical therapy was collected at enrollment, including OSA diagnosis date, CPAP start and stop dates, oral appliance trial, and reasons for discontinuation or non-adherence.

Results

The cohort consisted of 929 participants, 83% male, with a mean age (53.9 ± 10.5) years. Ninety percent (n = 835) had complete CPAP information including 47% (n = 435) who discontinued therapy prior to enrollment and 43% (n = 400) who were still attempting CPAP but had inadequate adherence. Abandonment rates were 60% at 1-year, 73% at 3-years, and 86% at 5-years. Oral appliance therapy was attempted by 171 patients for mean (1.8 ± 2.3) years, with 81% abandonment at 1 year, 89% at 3-years, and 94% at 5-years.

Conclusions

In this CPAP-refractory cohort, high rates of CPAP abandonment were reported in the first several years with approximately half of the participants not receiving any treatment despite being diagnosed for >5 years. Close clinical follow-up and consideration of alternative treatment options is indicated in all OSA patients in order to ensure adequate longitudinal care.

Upper Airway Stimulation for Obstructive Sleep Apnea: Patient-Reported Outcomes after 48 Months of Follow-up

Objective To assess patient-based outcomes of participants in a large cohort study-the STAR trial (Stimulation Therapy for Apnea Reduction)-48 months after implantation with an upper airway stimulation system for moderate to severe obstructive sleep apnea. Study Design A multicenter prospective cohort study. Setting Industry-supported multicenter academic and clinical setting. Subjects Participants (n = 91) at 48 months from a cohort of 126 implanted participants. Methods A total of 126 participants received an implanted upper airway stimulation system in a prospective phase III trial. Patient-reported outcomes at 48 months, including Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), and snoring level, were compared with preimplantation baseline. Results A total of 91 subjects completed the 48-month visit. Daytime sleepiness as measured by ESS was significantly reduced ( P = .01), and sleep-related quality of life as measured by FOSQ significantly improved ( P = .01) when compared with baseline. Soft to no snoring was reported by 85% of bed partners. Two patients required additional surgery without complication for lead malfunction. Conclusion Upper airway stimulation maintained a sustained benefit on patient-reported outcomes (ESS, FOSQ, snoring) at 48 months in select patients with moderate to severe obstructive sleep apnea.

Upper Airway Stimulation for Obstructive Sleep Apnea: Self-Reported Outcomes at 24 Months

OBJECTIVES

To evaluate the long-term (24-mo) effect of cranial nerve upper airway stimulation (UAS) therapy on patient-centered obstructive sleep apnea (OSA) outcome measures.

METHODS

Prospective, multicenter, cohort study of 126 patients with moderate to severe OSA who had difficulty adhering to positive pressure therapy and received the surgically implanted UAS system. Outcomes were measured at baseline and postoperatively at 12 mo and 24 mo, and included self- and bedpartner-report of snoring intensity, Epworth Sleepiness Scale (ESS), and Functional Outcomes of Sleep Questionnaire (FOSQ). Additional analysis included FOSQ subscales, FOSQ-10, and treatment effect size.

RESULTS

Significant improvement in mean FOSQ score was observed from baseline (14.3) to 12 mo (17.3), and the effect was maintained at 24 mo (17.2). Similar improvements and maintenance of effect were seen with all FOSQ subscales and FOSQ-10. Subjective daytime sleepiness, as measured by mean ESS, improved significantly from baseline (11.6) to 12 mo (7.0) and 24 mo (7.1). Self-reported snoring severity showed increased percentage of "no" or "soft" snoring from 22% at baseline to 88% at 12 mo and 91% at 24 mo. UAS demonstrated large effect size (> 0.8) at 12 and 24 mo for overall ESS and FOSQ measures, and the effect size compared favorably to previously published effect size with other sleep apnea treatments.

CONCLUSIONS

In a selected group of patients with moderate to severe OSA and body mass index ≤ 32 kg/m2, hypoglossal cranial nerve stimulation therapy can provide significant improvement in important sleep related quality-of-life outcome measures and the effect is maintained across a 2-y follow-up period.

Association of Autonomic Dysfunction and Mild Obstructive Sleep Apnea

BACKGROUND: Autonomic dysfunction (AD) has been independently associated with obstructive sleep apnea (OSA). Autonomic abnormalities are generally considered to be secondary to OSA. Autonomic dysfunction may also contribute to OSA. If AD contributes to OSA, we postulated that abnormalities may be present in mild OSA where the confounding causal effects of hypoxemia and sleep disruption are reduced.

OBJECTIVE: We evaluated autonomic function tests and sleep studies in a cohort of subjects with no known diagnosis of OSA.

METHODS: We prospectively enrolled a cohort without diagnosed OSA who were part of an ongoing study of vasomotor rhinitis (VMR) for testing. A battery of autonomic nervous system tests (sudomotor and cardiovagal), nonattended polysomnography, and three-site esophageal/pharyngeal pH monitoring were performed.

RESULTS: Twenty of 22 patients completed the test battery and 12 (60%) met criteria for OSA (Apnea/Hypopnea Index “AHI” >5 events/hour). AHI correlated to mean tilt table blood pressure decrease (R = 0.58, P = 0.007) and the Valsalva-mediated phase 2 mean blood pressure decrease (R = 0.52, P = 0.017). OSA severity was related to sympathetic but not parasympathetic abnormalities. No differences in blood pressure responses were related to age, oxygen desaturation nadir, gastroesophageal reflux, VMR, or sleepiness.

CONCLUSION: Autonomic abnormalities suggestive of decreased adrenergic tone are associated with mild OSA. These abnormalities may potentially be secondary but may also precede development of OSA. (Otolaryngol Head Neck Surg 2004;130: 643-8.)

Pharyngeal suspension suture with Repose bone screw for obstructive sleep apnea

OBJECTIVE

Multilevel surgery for obstructive sleep apnea syndrome (OSA) may improve success. This study's goal is to prospectively evaluate the feasibility and short-term subjective effectiveness of a new tongue-suspension technique.

METHODS

A multicenter nonrandomized open enrollment trial used the Repose device to treat tongue obstruction in 39 snoring and OSA patients. Outcomes include 1- and 2-month subjective reports of general health, snoring, and sleep.

RESULTS

Twenty-three patients completed 1 month and 19 completed 2 months of follow-up. In OSA patients, activity level, energy/fatigue, and sleepiness improved. Two-month outcomes were less (activity level, energy/fatigue, and sleepiness). Fewer changes were observed in snorers than in OSA patients. There were 6 complications (18%), including sialadenitis (4), gastrointestinal bleeding (1), and dehydration (1) after the procedure.

CONCLUSION

A pharyngeal suspension suture changes subjective outcomes. Improvement is incomplete. The procedure is nonexcisional, but significant complications may occur. Further evaluation is required to demonstrate effectiveness.

Relationship of Snoring and Sleepiness as Presenting Symptoms in a Sleep Clinic Population

Objectives:

Sleepiness has traditionally been considered medically the cardinal symptom of obstructive sleep apnea syndrome. Snoring is perceived as a social or cosmetic complaint. Without independent medical morbidity, snoring identification and treatment is not a major focus in sleep medicine. We speculate that snoring is a major independent symptom. To evaluate how patients rated snoring symptom severity, we compared the relative significance of a sleep clinic population's presenting symptoms of snoring and sleepiness.

Methods:

We performed a retrospective analysis of 770 consecutive patients who completed sleep intake evaluation forms at the initial clinic visit, including standardized forms for both sleepiness and snoring using previously validated visual analog scales. Data on symptom magnitude (scale of 1 to 10), symptom importance (scale of 1 to 5), a combined symptom product score consisting of magnitude multiplied by importance (MIP; scale of 1 to 50), the Epworth Sleepiness Scale (ESS; n = 599), and the apnea-hypopnea index (AHI; n = 482; mean ± SD, 35.6 ± 31.9 events per hour) were collected.

Results:

The mean snoring measures (magnitude, importance, and MIP) were greater than those for sleepiness (MIPsnoring of 32.7 ± 14.8 versus MIPsleepiness of 22.4 ± 14.2, p <.001). Snoring scored higher than sleepiness in 72% of individuals. To assess whether sleep apnea or sleepiness severity affected symptom scores, we stratified the subgroup with sleep studies into quartiles by AHI and ESS score. Snoring consistently scored higher than sleepiness in most AHI and ESS quartiles (p <.01). Only in the most severe ESS quartile did any sleepiness measure (importance) score higher than the snoring measure (p <.05).

Conclusions:

The presenting symptoms of snoring are larger in magnitude, importance, and severity than those of sleepiness in a broad population of patients with sleep disorders and sleep-disordered breathing irrespective of severity of sleep apnea or sleepiness. Symptoms of major significance are clinically relevant to identifying, diagnosing, and treating patients. Failure of medical providers to appreciate the impact of snoring on this population may affect attempts to identify, diagnose, and treat patients with sleep-disordered breathing.

Multilevel Temperature-Controlled Radiofrequency for Obstructive Sleep Apnea: Extended Follow-Up

OBJECTIVE: To determine long-term effectiveness of multilevel (tongue and palate) temperature-controlled radiofrequency tissue ablation (TCRFTA) for patients with obstructive sleep apnea syndrome (OSAS).

STUDY DESIGN AND SETTING: Prospective, 2-institution case series. Twenty-nine subjects with mild to moderate OSAS and who were at least 1 year from completion of multilevel TCRFTA were included, representing a subset of subjects who were enrolled in a previously published controlled trial. Exclusion criteria for this extended follow-up study included any additional treatment for OSAS after completion of TCRFTA.

RESULTS: Median follow-up was 23 months. Daytime sleepiness and OSAS-related quality of life were significantly improved at extended follow-up (both P 0.001). Median reaction time testing and apnea-hypopnea index (AHI) were also significantly improved at long-term follow-up ( P = 0.03 and 0.01). Body mass index was unchanged ( P = 0.94).

CONCLUSIONS: Multilevel TCRFTA treatment of mild to moderate OSAS resulted in prolonged improvement in daytime somnolence, OSAS-related quality of life, psychomotor vigilance, and AHI in this group of subjects at extended follow-up.

Reduction of C-reactive protein with surgical treatment of obstructive sleep apnea hypopnea syndrome

OBJECTIVES: To determine whether surgical treatment of obstructive sleep apnea/hypopnea syndrome (OSAHS) has an impact on C-reactive protein (CRP) level.

STUDY DESIGN: Prospective study of 34 consecutive subjects undergoing surgical treatment for OSAHS. CRP levels were evaluated preoperatively and 2 months postoperatively. The most commonly performed procedure was uvulopalatopharyngoplasty (UPPP) combined with radiofrequency tongue base reduction.

RESULTS: Seven patients were treated for mild OSAHS and 23 were treated for moderated/severe OSAHS; 18 of 23 patients with moderate/severe disease had relative elevation of preoperative CRP levels. Mean CRP level decreased from 0.33 mg/dL preoperatively to 0.16 mg/dL postoperatively ( P = 0.003). Even patients who did not achieve complete “cure" by classical polysomnography (PSG) criteria may benefit from lowered CRP levels. All patients, however did achieve reduction in apnea hypopnea index and improvement in clinical symptoms.

CONCLUSIONS: Levels of CRP were elevated preoperatively but decreased after surgical treatment. Therefore, OSAHS surgical treatment may be useful in reduction of CRP levels in patients who will not or cannot accept nasal-CPAP therapy.

Polysomnography indexes are discordant with quality of life, symptoms, and reaction times in sleep apnea patients

OBJECTIVE: We tested whether polysomnography (PSG) indexes were associated with sleepiness, quality of life, or reaction times at baseline and as outcome measures following surgical or sham treatment for patients with obstructive sleep apnea syndrome (OSAS).

STUDY DESIGN AND METHODS: Mild-moderate OSAS subjects were measured before and 8 weeks after surgical or sham treatment in this prospective longitudinal study. Measures included standard PSG indexes, sleepiness, quality of life, and reaction times. Associations were examined with Spearman correlations and multivariate linear regression.

RESULTS: Correlations between baseline PSG and non-PSG measures ranged from −0.22 to 0.25 (n, 87 subjects; mean correlation, 0.00 ± 0.11), with one positive association significant of 56 tested (arousal index and SF36 Mental Component Summary, r, 0.25; P = 0.03). Correlations between change in PSG and non-PSG measures ranged from −0.37 to 0.35 (n, 54 subjects; mean correlation, −0.05 ± 0.19), with no significant positive association of 56 tested. Regression analyses confirmed these results.

CONCLUSIONS: PSG indexes are not consistently associated with sleepiness, quality of life, or reaction time, both at baseline and as outcome measures in patients with mild-moderate OSAS. PSG indexes may not quantify some important aspects of OSAS disease burden or treatment outcome. Clinically important outcomes should be measured directly. EBM rating: A.

Transpalatal Advancement Pharyngoplasty Outcomes Compared With Uvulopalatopharygoplasty

Objective:

Uvulopalatopharyngoplasty (UPPP) success rates in patients classified with Friedman stage 3 is reported as 8%. Surgical failure may result from persistent obstruction at the palate, which may be addressed by pharyngoplasty with palatal advancement (PA). The effectiveness of PA versus UPPP was evaluated by using polysomnographic outcomes in a retrospective cohort of patients classified with Friedman stage 3.

Methods:

Surgical records were reviewed for PA (n = 47) and UPPP (n = 124). Clinical records were reviewed and reclassified by Friedman stage. Respiratory data were collected from overnight polysomnography. Statistical analysis was conducted of continuous variables (ANOVA), categorical variables (χ 2 ), and adjusted odds ratios by using logistic regression.

Results:

PA (n = 30) and UPPP (n = 44) did not differ in baseline apnea hypopnea index (AHI), age, or BMI. Both PA (48.3 ± 24.6 to 19.8 ± 16.8 events per hour, P < 0.000) and UPPP (47.9 ± 30.0 to 30.9 ± 24.2 events per hour, P < 0.000) improved with surgery. In the PA group, final AHI was lower (17.1 ± 30.1 versus 28.5 ± 25.6, P < 0.04) and postoperative change was greater (30.9 ± 24.2 versus 19.8 ± 16.8, P < 0.02). For patients with Friedman stage 3, odds ratio of having an AHI of <20 events per hour and a greater than 50% reduction with PA compared with UPPP was 3.80 (95% CI, 1.41-10.29, P < 0.013). Adjusted for age, body mass index, preoperative apnea severity, and tongue-base surgery, OR was 5.77 (95% CI of 1.80-17.98).

Conclusions:

Polysomnographic outcomes using AHI support the use of palatopharyngoplasty using palatal advancement as an effective treatment of obstructive sleep apnea. PA may offer benefit over UPPP alone in patients classified with Friedman stage 3.

Efficacy of Upper Airway Stimulation on Collapse Patterns Observed during Drug-Induced Sedation Endoscopy

OBJECTIVE

To describe upper airway collapse patterns observed on drug-induced sedation endoscopy (DISE) during screening for a clinical trial and to evaluate the impact of collapse patterns found on preoperative DISE on response rates to upper airway stimulation (UAS) therapy.

STUDY DESIGN

Retrospective review of an ongoing prospective multi-institutional cohort study.

SETTING

Twenty-two participating institutions of the STAR trial.

SUBJECTS AND METHOD

In total, 222 subjects were screened with DISE to determine eligibility for an implantable UAS device. Supine laryngoscopy was performed during moderate sedation (propofol and/or midazolam). Airway collapse pattern and severity were graded at 4 levels, including velum, oropharynx, tongue base, and epiglottis (VOTE classification). Patients with complete concentric collapse (CCC) at the velum were excluded from implantation.

RESULTS

The CCC at the velum was observed in 52 (23%) of screened subjects, and these subjects were subsequently excluded from implantation. Of the 170 subjects without CCC at the velum, 126 (77%) underwent implantation: 121 (96%) had multilevel collapse and 5 (4%) had single-level collapse. When comparing preimplantation DISE findings, UAS responders at 12 months had lower baseline VOTE scores compared with therapy nonresponders.

CONCLUSION

Drug-induced sedation endoscopy is an efficient and safe method for determining UAS eligibility and has the potential to identify UAS nonresponders. Most patients had multilevel airway collapse, illustrating the limitations of single-level upper airway surgery in treating obstructive sleep apnea. Upper airway stimulation is effective therapy for most patients with multilevel airway collapse; however, patients with complete anterior-posterior or lateral soft palate and/or epiglottic collapse may be at increased risk of therapy failure.

Three-Year Outcomes of Cranial Nerve Stimulation for Obstructive Sleep Apnea: The STAR Trial

OBJECTIVE

To describe the 36-month clinical and polysomnography (PSG) outcomes in an obstructive sleep apnea (OSA) cohort treated with hypoglossal cranial nerve upper airway stimulation (UAS).

STUDY DESIGN

A multicenter prospective cohort study.

SETTING

Industry-supported multicenter academic and clinical setting.

SUBJECTS

Participants (n = 116) at 36 months from a cohort of 126 implanted participants.

METHODS

Participants were enrolled in a prospective phase III trial evaluating the efficacy of UAS for moderated to severe OSA. Prospective outcomes included apnea-hypopnea index, oxygen desaturation index, other PSG measures, self-reported measures of sleepiness, sleep-related quality of life, and snoring.

RESULTS

Of 126 enrolled participants, 116 (92%) completed 36-month follow-up evaluation per protocol; 98 participants additionally agreed to a voluntary 36-month PSG. Self-report daily device usage was 81%. In the PSG group, 74% met the a priori definition of success with the primary outcomes of apnea-hypopnea index, reduced from the median value of 28.2 events per hour at baseline to 8.7 and 6.2 at 12 and 36 months, respectively. Similarly, self-reported outcomes improved from baseline to 12 months and were maintained at 36 months. Soft or no snoring reported by bed partner increased from 17% at baseline to 80% at 36 months. Serious device-related adverse events were rare, with 1 elective device explantation from 12 to 36 months.

CONCLUSION

Long-term 3-year improvements in objective respiratory and subjective quality-of-life outcome measures are maintained. Adverse events are uncommon. UAS is a successful and appropriate long-term treatment for individuals with moderate to severe OSA.

Expansion sphincter pharyngoplasty for the treatment of OSA: a systemic review and meta-analysis

This study seeks to determine the success rates of the expansion sphincter pharyngoplasty and its variants on the treatment of obstructive sleep apnea (OSA). Systematic review and meta-analysis. Two independent searches of MEDLINE, Google Scholar, Cochrane Library and Evidence Based Medicine Reviews to identify publications relevant to OSA and expansion pharyngoplasty. All relevant studies published before 31 March 2015 were included. Five studies were included in the systematic review and meta-analysis. The numbers of patients in each paper ranged from 10 to 85 (total = 155), and mean age ranged from 8 to 56 years. Substantial and consistent improvement in PSG outcomes were observed post-expansion pharyngoplasty patients, with or without multilevel surgery groups. The results showed that the expansion pharyngoplasty technique has significantly lower AHI than control group [Standardised mean difference -7.32, 95 %CI (-11.11, -3.52), p = 0.0002]; however, substantial heterogeneity between these studies were observed. The mean pre-operative AHI (in the five papers) improved from 40.0 ± 12.6 to 8.3 ± 5.2 post-operatively. The overall pro-rated pooled success rate for all the patients was 86.3 %. The expansion pharyngoplasty is effective in the management of patients with OSA.

Upper Airway Stimulation for Obstructive Sleep Apnea: Durability of the Treatment Effect at 18 Months

OBJECTIVE

To determine the stability of improvement in polysomnographic measures of sleep disordered breathing, patient reported outcomes, the durability of hypoglossal nerve recruitment and safety at 18 months in the Stimulation Treatment for Apnea Reduction (STAR) trial participants.

DESIGN

Prospective multicenter single group trial with participants serving as their own controls.

SETTING

Twenty-two community and academic sleep medicine and otolaryngology practices.

MEASUREMENTS

Primary outcome measures were the apnea-hypopnea index (AHI) and the 4% oxygen desaturation index (ODI). Secondary outcome measures were the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire (FOSQ), and oxygen saturation percent time < 90% during sleep. Stimulation level for each participant was collected at three predefined thresholds during awake testing. Procedure- and/or device-related adverse events were reviewed and coded by the Clinical Events Committee.

RESULTS

The median AHI was reduced by 67.4% from the baseline of 29.3 to 9.7/h at 18 mo. The median ODI was reduced by 67.5% from 25.4 to 8.6/h at 18 mo. The FOSQ and ESS improved significantly at 18 mo compared to baseline values. The functional threshold was unchanged from baseline at 18 mo. Two participants experienced a serious device-related adverse event requiring neurostimulator repositioning and fixation. No tongue weakness reported at 18 mo.

CONCLUSION

Upper airway stimulation via the hypoglossal nerve maintained a durable effect of improving airway stability during sleep and improved patient reported outcomes (Epworth Sleepiness Scale and Functional Outcomes of Sleep Questionnaire) without an increase of the stimulation thresholds or tongue injury at 18 mo of follow-up.

The Relationship between Metformin and Obstructive Sleep Apnea

OBJECTIVES

This study aimed to assess if metformin had any associations with the prevalence of obstructive sleep apnea in an adult type 2 diabetes population in the Midwest.

HYPOTHESIS

Use of metformin is associated with decreased prevalence of obstructive sleep apnea in a adult type 2 diabetes population.

METHODS

A retrospective secondary database analysis was carried out with metformin use by patients with type 2 diabetes as the primary variable of interest and obstructive sleep apnea status as the primary outcome. A sample population of 9,853 type 2 diabetes patients with one year of follow-up was used. Other variables that were analyzed included age, gender, race, hypertension, Congestive Heart Failure, Hemoglobin A1c (HbA1c), and Body Mass Index. A p-value of <0.01 was considered significant.

RESULTS

Metformin usage was not significantly associated with obstructive sleep apnea prevalence (Odds Ratio: 1.17, Confidence Interval: 1.00-1.36, p = 0.049), but trended in the direction where metformin usage was associated with having obstructive sleep apnea. Lower HbA1c was found to be significantly associated with lower prevalence of obstructive sleep apnea (p <0.001). The rest of the variables followed previously published associations.

CONCLUSIONS

Metformin therapy may improve sleep quality, but it may not be through methods that reduce the likelihood of developing obstructive sleep apnea. Future studies that can prove causation about this association should be considered.

Randomized controlled withdrawal study of upper airway stimulation on OSA: short- and long-term effect

OBJECTIVE

To assess the efficacy and durability of upper airway stimulation via the hypoglossal nerve on obstructive sleep apnea (OSA) severity including objective and subjective clinical outcome measures.

STUDY DESIGN

A randomized controlled therapy withdrawal study.

SETTING

Industry-supported multicenter academic and clinical setting.

SUBJECTS

A consecutive cohort of 46 responders at 12 months from a prospective phase III trial of 126 implanted participants.

METHODS

Participants were randomized to either therapy maintenance ("ON") group or therapy withdrawal ("OFF") group for a minimum of 1 week. Short-term withdrawal effect as well as durability at 18 months of primary (apnea hypopnea index and oxygen desaturation index) and secondary outcomes (arousal index, oxygen desaturation metrics, Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, snoring, and blood pressure) were assessed.

RESULTS

Both therapy withdrawal group and maintenance group demonstrated significant improvements in outcomes at 12 months compared to study baseline. In the randomized assessment, therapy withdrawal group returned to baseline, and therapy maintenance group demonstrated no change. At 18 months with therapy on in both groups, all objective respiratory and subjective outcome measures showed sustained improvement similar to those observed at 12 months.

CONCLUSION

Withdrawal of therapeutic upper airway stimulation results in worsening of both objective and subjective measures of sleep and breathing, which when resumed results in sustained effect at 18 months. Reduction of obstructive sleep apnea severity and improvement of quality of life were attributed directly to the effects of the electrical stimulation of the hypoglossal nerve.

Ask the Experts: Sleep Surgery Potpourri

Program Description:

Modification of uvulopalatopharyngoplasty (UPPP) as well as variation in treatment of hypopharyngeal obstruction are numerous. Selecting the right technique for the right patient often becomes the most difficult decision in treatment planning. It is often unclear if the proponents of a particular technique apply their “modifications” for every case or if there is a selection process. The purpose of this miniseminar is to present specific cases and hear the opinion of 5 experts on how they would treat the same patient.

Educational Objectives:

(1) Use the appropriate patient selection for a classic UPPP. (2) Determine when uvula preservation techniques are appropriate. (3) Examine the current thinking in tongue base reduction.

Randomized Treatment Withdrawal of Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea

Objectives:

Describe the therapeutic effect of upper airway stimulation (UAS) therapy withdrawal on objective and subjective measures of sleep apnea severity.

Methods:

From a cohort of 126 participants in a prospective therapy effectiveness trial, 46 subjects were randomized to therapy “ON” and “OFF” groups. Primary outcomes measures were apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) changes and secondary outcome measures included Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), sleep architecture, hypoxemia, snoring, and blood pressure.

Results:

Groups did not differ at pretreatment baseline or at 12 months of therapy in polysomnography or self-reported measures. Following randomized controlled trial (RCT) therapy withdrawal, change in AHI and ODI significantly differed in “ON” and “OFF” groups (1.7 versus 18.2 and 1.6 versus 17.0 events/hour P < .0001). Therapy withdrawal worsened ESS, FOSQ, snoring, hypoxemia, and arousal index in the therapy “OFF” but no change was observed in the “ON” group ( P < .001). The therapy “ON” group demonstrated a reduction in blood pressure at 12 months compared to baseline which was maintained through the RCT.

Conclusions:

Withdrawal of therapeutic UAS results in relapse of both subjective and objective measures of OSA.

Hypoglossal Nerve Stimulation Therapy for Obstructive Sleep Apnea

Program Description:

Obstructive sleep apnea (OSA) significantly affects sleep, daytime function, quality of life, public safety, and cardiovascular risk. Although positive pressure remains the primary treatment, suboptimal adherence rates necessitate alternative treatment strategies. Hypoglossal nerve stimulation is a new and emerging treatment option with published prospective clinical trial data. Sleep-boarded otolaryngologists will review the physiology and basic science of upper airway stimulation, demonstrate the current technology and surgical procedure, present safety and efficacy data from recent multicenter clinical trials, and discuss patient selection and cost-effectiveness. A panel will explore future directions and the advantages/disadvantages of this technology as it compares to other sleep apnea treatment options.

Educational Objectives:

(1) Examine the pathophysiology of OSA with a particular focus on the neuromuscular control mechanisms. (2) Interpret the basic science and feasibility studies on hypoglossal nerve stimulation and describe the current technology and surgical procedure. (3) Report the safety, efficacy, and cost-effectiveness data from published prospective multicenter clinical trials.

Controversies in Management of the Nasal Airway and Sleep Disorders

Program Description:

Surgical and medical management of the nasal airway has traditionally not been considered primary indication for sleep disorders’ treatment. Controversy exists over nasal surgery as primary treatment of snoring and sleep apnea. Algorithms to manage sleep-disordered breathing often ignore or dismiss the nasal airway. This miniseminar addresses the following controversies: (1) Is the nasal airway an important contributor to sleep disorders? (2) Does nasal surgery affect sleep? (3) Does nasal treatment affect the use of continuous positive airway pressure? and (4) What is the role and documented effect of nasal surgery sleep apnea treatment in adults and children?

Educational Objectives:

(1) Justify using appropriate evidence-based outcome metrics of medical and surgical treatment of the nose for specific sleep-related breathing disorders. (2) Compare medical outcomes of sleep apnea treatment with and without treatment of nasal obstruction. (3) Describe potential differences and obstacles in treating nasal obstruction using traditional definitions versus treating it as a spectrum of sleep disordered breathing.

Upper-airway stimulation for obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea.

METHODS

Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial.

RESULTS

The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%.

CONCLUSIONS

In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

Nasal Symptoms, Resistance, and AHI Contributions to Subjective Sleep Outcomes

Objectives:

The contribution of nasal obstruction to sleep related quality of life is poorly understood. This study assesses the contribution of: 1) nasal symptoms and effective nasal resistance;2) AHI to sleep-related quality of life.

Methods:

70 unselected adult patients (age 52.2 (13.9) years) undergoing polysomnography at an academic sleep center were evaluated with four phase rhinomanometry (RhinoLab, Rendsburg, Germany ) in the upright and supine body positions and completed validated quality of life measures.

Results:

AHI demonstrated no associations with nasal obstruction symptom questionnaire (NOSE), insomnia score (PSQI), hypersomnia (ESS), or functional quality of life (FOSQ-10). However, both nasal symptoms (NOSE) and resistance (Rsupine/effective) were associated with sleep metrics. NOSE was associated with insomnia, hypersomnia, and QOL (r = 0.44,0.29, and 0.40 respectively, all p < 0.01) while Rsupine/effective was associated with hypersomnia (r=0.24,p<0.02) and a trend to insomnia (p< 0.09). No association with change in upright to supine resistance was observed. In the group with OSA (AHI > 5/hr., n= 49) and without OSA (AHI < 5/hr.,n=21) nasal symptoms and Rsupine/effective maintained associations (r=0.30 and 0.32 p<0.05) with hypersomnia (ESS) but not AHI (p=NS) in either group.

Conclusions:

In a sleep lab cohort referred for evaluation of possible sleep disordered breathing, both subjective and objective measures of nasal obstruction but not AHI contribute to sleep related subjective outcomes. Further research is needed on the nasal contribution to sleep disorders independent of AHI.

Safety and Effectiveness of Upper Airway Stimulation via the Hypoglossal Nerve for Obstructive Sleep Apnea

Objectives:

Determine safety and effectiveness of upper airway stimulation for treatment of obstructive sleep apnea (OSA) in a prospective, multi-center trial; with subsequent randomized, controlled therapy withdrawal evaluation.

Methods:

This study enrolled and screened 900 adult subjects. Inclusion criteria were moderate-to-severe OSA (apnea-hypopnea index [AHI] 20-50), prior continuous positive airway pressure (CPAP) failure or intolerance, and body mass index (BMI) < 32. All qualified subjects underwent further screening with drug-induced sleep endoscopy (DISE) to exclude those with concentric palatal collapse. 126 subjects meeting all inclusion/exclusion criteria then underwent surgical implantation of a right sided unilateral hypoglossal nerve stimulation electrode, with pulse generator and respiration sensor (Upper Airway Stimulation System, Inspire Medical Systems, Minnesota). Patients were evaluated at 2, 6, and 12 months. Primary outcome measures included AHI, oxygen desaturation index, Epworth Sleepiness Scale, and Functional Outcomes of Sleep Questionnaire at 12 months. Therapy withdrawal effect was evaluated by randomizing a subset of consecutive responders to one week of on or off therapy for controlled comparison.

Results:

All 126 subjects were successfully implanted. In general, subjects were middle aged (mean 54.5 ± 10.2 yrs), male (83%), with severe OSA (mean baseline AHI 32.0 ± 11.8). Transient dysarthria and dysphagia were noted in a minority of patients. Over 70% of subjects have completed the study, with the remaining scheduled to complete 12 month evaluation by April, 2013. Final safety and effectiveness outcomes will be presented.

Conclusions:

Implantation of an upper airway stimulation system involving unilateral hypoglossal nerve electrode placement appears safe and feasible, with transient dysarthria occurring infrequently. Effectiveness will be addressed after completion of 12 month follow-up for all subjects.