Pharyngeal Collapse Research Articles

O026 Effect of oral appliance therapy on OSA endotypes

Abstract Introduction Long term CPAP therapy alters OSA endotypes (e.g., reduces loop gain and the arousal threshold). However, while oral appliance therapy (OAT) is known to improve upper airway collapsibility, its effects on non-anatomical OSA endotypes are unclear. Methods To investigate the effects of OAT on polysomnographic estimates of OSA endotypes we studied 102 people with OSA (AHI=34±20 events/h) pre vs. post-treatment (following 4-6 weeks OAT acclimatization). AHI and endotypic traits were compared between the diagnostic and OAT study visits. Results OAT reduced the AHI by ~50% (30 [25-39] vs. 15 [12-19], median, 95% confidence interval, p<0.01). Passive pharyngeal collapsibility (94 [92-95] vs. 96 [95-97]% eupnea), active pharyngeal collapsibility (98 [95-100] vs. 102 [101-103]% eupnea) and pharyngeal muscle compensation (3.6 [1.2-5.1] vs 4.9 [3.7-6.5]% eupnea) improved with OAT (all p<0.01). The respiratory arousal threshold (116 [114-122] vs. 109 [106-111]% eupnea, p<0.01) and ventilatory response to arousal (31 [28-35] vs. 23 [20-32]% eupnea, p=0.03) decreased. Loop gain did not systematically change overall (0.43 [0.39-0.47] vs. 0.40 [0.38-0.42], p=0.16). However, loop gain reduced in OAT responders (>50% reduction in AHI) (0.42 [0.39-0.45] vs. 0.38 [0.34-0.4] dimensionless, p<0.01). Conclusions Oral appliance therapy improves upper airway collapsibility and pharyngeal muscle compensation and reduces the ventilatory response to arousal and loop gain in responders. Like CPAP, OAT also decreases the arousal threshold. These findings provide new insight into the mechanisms of improvement in OSA with oral appliance therapy.

Pathophysiology Underlying Demographic and Obesity Determinants of Sleep Apnea Severity.

Rationale: Sleep apnea is the manifestation of key endotypic traits, including greater pharyngeal collapsibility, reduced dilator muscle compensation, and elevated chemoreflex loop gain. Objectives: We investigated how endotypic traits vary with obesity, age, sex, and race/ethnicity to influence sleep apnea disease severity (apnea-hypopnea index [AHI]). Methods: Endotypic traits were estimated from polysomnography in a diverse community-based cohort study (Multi-Ethnic Study of Atherosclerosis, N = 1,971; age range, 54-93 yr). Regression models assessed associations between each exposure (continuous variables per 2 standard deviations [SDs]) and endotypic traits (per SD) or AHI (events/h), independent of other exposures. Generalizability was assessed in two independent cohorts. Results: Greater AHI was associated with obesity (+19 events/h per 11 kg/m2 [2 SD]), male sex (+13 events/h vs. female), older age (+7 events/h per 20 yr), and Chinese ancestry (+5 events/h vs. White, obesity adjusted). Obesity-related increase in AHI was best explained by elevated collapsibility (+0.40 SD) and greater loop gain (+0.38 SD; percentage mediated, 26% [95% confidence interval (CI), 20-32%]). Male-related increase in AHI was explained by elevated collapsibility (+0.86 SD) and reduced compensation (-0.40 SD; percentage mediated, 57% [95% CI, 50-66%]). Age-related AHI increase was explained by elevated collapsibility (+0.37 SD) and greater loop gain (+0.15 SD; percentage mediated, 48% [95% CI, 34-63%]). Increased AHI with Chinese ancestry was explained by collapsibility (+0.57 SD; percentage mediated, 87% [95% CI, 57-100]). Black race was associated with reduced collapsibility (-0.30 SD) and elevated loop gain (+0.29 SD). Similar patterns were observed in the other cohorts. Conclusions: Different subgroups exhibit different underlying pathophysiological pathways to sleep apnea, highlighting the variability in mechanisms that could be targeted for intervention.

S239 The Association of Obstructive Sleep Apnea and Clostridium difficile: A Nationwide Inpatient Sample Analysis

Introduction: Obstructive sleep apnea (OSA) is a sleep disorder involving repeated apneic episodes during sleep due to an obstruction of the airflow. OSA predisposes individuals to community-acquired pneumonia due to upper airway microaspiration. Furthermore, hypoxia due to intermittent pharyngeal collapses is shown to cause a pro-inflammatory state and reduced NK cell cytotoxicity and maturation, which can increase the risks of infections due to suppression of immune response. Increased incidence of infections in the OSA subgroup leads to increased use of antibiotics. Antibiotic exposure is the primary risk factor for developing Clostridium difficile (C. diff) infection. In synchrony with this notion, the primary purpose of this study was to determine the association between OSA and C. diff infection. Methods: A retrospective analysis was conducted using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS). Patients without C. diff were analyzed (control) and were randomly selected and matched to each patient who did have C. diff. Weighted logistic regression models were used to calculate the association between OSA and C. diff for different comorbidities. Results: A total of 7,135,090 patients were included in our analysis. The prevalence of C. diff was significantly higher in patients with OSA (1.19% vs. 1.00%, p< 0.0001). In addition, multiple comorbidities were significantly elevated in the OSA group compared to those without OSA, including alcohol and obesity (p< 0.0001). Conclusion: This study uses ICD-10-CM codes with a specific search code for OSA. Our large population database shows a significant association between OSA and C. diff. One of the hypotheses describing this increased association could be more antibiotic exposure in OSA subgroup leading to C. diff. Additional studies are needed to confirm or refute this association.

Sleep endoscopy as a complementary diagnostic method for snoring and sleep apnea.

ABSTRACTObstructive sleep apnea is a disorder characterized by complete or incomplete and recurrent upper airway collapse induced by sleep. Several diagnostic methods for obstructive sleep apnea are used, but only sleep endoscopy allows an endoscopic assessment of pharyngeal collapse during sedation. It is essential to carry out sleep endoscopy following a systematic institutional protocol, in preestablished stages, to ensure better reproducibility and reliability of the results found. Sleep endoscopy has few limitations and is a safe test, with a low risk of complications.

Identifying the site and pattern of pharyngeal collapse using polysomnographic airflow shapes

Identifying the site and pattern of pharyngeal collapse using polysomnographic airflow shapes

Within-night repeatability and long-term consistency of sleep apnea endotypes: the Multi-Ethnic Study of Atherosclerosis and Osteoporotic Fractures in Men Study.

Obstructive sleep apnea (OSA) is characterized by multiple "endotypic traits," including pharyngeal collapsibility, muscle compensation, loop gain, and arousal threshold. Here, we examined (1) within-night repeatability, (2) long-term consistency, and (3) influences of body position and sleep state, of endotypic traits estimated from in-home polysomnography in mild-to-severe OSA (apnea-hypopnea index, AHI > 5 events/h). Within-night repeatability was assessed using Multi-Ethnic Study of Atherosclerosis (MESA): Traits derived separately from "odd" and "even" 30-min periods were correlated and regression (error vs. N windows available) provided a recommended amount of data for acceptable repeatability (Rthreshold = 0.7). Long-term consistency was assessed using the Osteoporotic Fractures in Men Study (MrOS) at two time points 6.5 ± 0.7 years apart, before and after accounting for across-year body position and sleep state differences. Within-night dependence of traits on position and state (MESA plus MrOS data) was estimated using bootstrapping. Within-night repeatability for traits ranged from R = 0.62-0.79 and improved to R = 0.69-0.83 when recommended amounts of data were available (20-35 7-min windows, available in 94%-98% of participants); repeatability was similar for collapsibility, loop gain, and arousal threshold (R = 0.79-0.83), but lower for compensation (R = 0.69). Long-term consistency was modest (R = 0.30-0.61) and improved (R = 0.36-0.63) after accounting for position and state differences. Position/state analysis revealed reduced loop gain in REM and reduced collapsibility in N3. Endotypic traits can be obtained with acceptable repeatability. Long-term consistency was modest but improved after accounting for position and state changes. These data support the use of endotypic assessments in large-scale epidemiological studies. The data used in the manuscript are from observational cohort studies and are not a part of the clinical trial.

Holistic care for obstructive sleep apnea (OSA) with an emphasis on restoring nasal breathing: A review and perspective.

Obstructive sleep apnea (OSA) is characterized by partial or complete airway blockage during sleep. Nocturnal nasal obstruction usually leads to mouth breathing while sleeping, which worsens sleep apnea by aggravating tongue base and lateral pharyngeal wall collapse. The pathogenesis of OSA is multifactorial, and the precipitating factors vary significantly among individuals. Although continuous positive airway pressure (CPAP) is considered the first-line therapy for OSA, its adherence rate remains a challenge. Oral appliances are more suitable for simple snorers or patients with mild OSA. Maxillomandibular advancement (MMA) is highly effective for treating those with mandibular retrognathia and moderate-to-severe OSA. Intrapharyngeal surgeries yield favorable outcomes in patients with large tonsils and low tongue resting position (Friedman Stage I); however, their efficacy declines with time. Each therapy has its own strength and weakness; thus, the principle of multimodality treatment should be adopted. Nasal surgery plays an indispensable role in the holistic care for OSA. In addition to alleviating nasal congestion, nasal surgery significantly reduces snoring intensity and daytime sleepiness, which improves the quality of life of patients with OSA. Although it significantly reduces the respiratory disturbance index, its effect on the apnea-hypopnea index remains controversial. A combination of nasal surgery and multilevel pharyngeal surgery may result in better prognosis. Nasal surgery can significantly reduce the therapeutic pressure and improve the CPAP compliance of patients undergoing CPAP therapy. In conclusion, multimodality treatment and holistic care for OSA should involve nasal surgery for optimizing treatment outcomes.

Management of pharyngeal collapse in patients affected by moderate obstructive sleep apnoea syndrome.

SUMMARYObjectiveThis study reports our experience in a selected cohort of patients affected by mild-moderate OSAS, without tonsillar obstruction, and treated with pharyngoplasty.MethodsIn a case-control retrospective study, we compared modified expansion sphincter pharyngoplasty (MESP) to modified barbed reposition pharyngoplasty (MBRP) in adult patients with oropharyngeal transversal collapse with a BMI ≤ 30 kg/m2, and mild-moderate obstructive sleep apnoea syndrome (OSAS). A clinical evaluation, including collection of anthropometric data and sleep endoscopy, was performed. Six months after surgery, symptoms recording, clinical evaluation and polysomnography (PSG) were repeated.ResultsWe enrolled 20 patients: 10 treated with MESP and 10 treated with MBRP. Mean apnoea-hypoapnoea index (AHI) was 22.8 (± 5.63). We observed in both groups a significant reduction of AHI and oropharyngeal obstruction (p = 0.01), with a success rate, according with Sher’s criteria, of 90% for MESP and 80% for MBRP, respectively. Post-surgical pain and snoring reduction were significantly lower with MBRP.ConclusionsWe recorded similar success rates for both techniques. MBRP may be considered better than MESP due to less surgical time, no potential mucosal damage, absence of knots, and faster recovery with less pain.

0744 A Comparison of Visual and Physiologic Assessments of Upper Airway Collapse during Drug-Induced Sleep Endoscopy (DISE)

Abstract Introduction The VOTE score, critical closing pressure (Pcrit), and therapeutic CPAP levels are assessments that quantify upper airway collapse by either subjective visual scoring or objective pressure-flow analysis. We hypothesized that there would be an association between collapse severity and physiologic metrics (VOTE versus Pcrit and PAP levels, respectively) acquired during drug-induced sleep endoscopy (DISE). Methods This prospective cohort study evaluated 100 consecutive patients with obstructive sleep apnea (OSA) who underwent DISE with application of nasal positive airway pressure between June 3rd, 2020 and June 11th, 2021. Patients were assigned a VOTE score of 0, 1, or 2 indicating no collapse, partial collapse, or complete collapse at the velum, oropharynx, tongue base, and epiglottis, respectively. We assessed two metrics of pharyngeal collapsibility with progressive increases in nasal pressure: (1) the pressure at which inspiratory airflow commences (critical pressure, Pcrit), and (2) the pressure at which inspiratory flow limitation is abolished (pharyngeal opening pressure, PhOP). Our analysis examined the association between the composite VOTE score [0-8 units] and collapsibility metrics. Results Ninety-one patients met inclusion criteria for VOTE scoring; of these, 87 were included for PhOP analysis and 79 for Pcrit analysis. The cohort was 76% male, mean (SD) age was 54.7 (14.1) years, body-mass index was 29.7 (4.9), and AHI was 30.3 (20.9). Composite VOTE score was positively associated with Pcrit (β = 0.88 ± 0.38 cm H2O per unit, standardized estimate = 0.26, p=0.023). We found no significant association between the composite VOTE score and PhOP (β = 0.57 ± 0.40 cm H2O per unit, standardized estimate = 0.15, p=0.162). Conclusion Our findings suggest that visual and physiological assessments of upper airway collapsibility provide both overlapping and complementary information in characterizing upper airway mechanics. Measures of pharyngeal collapsibility during DISE can be used to model the ultimate impact of therapeutic maneuvers on OSA. Future studies investigating the utility of each assessment both in isolation and in combination for predicting OSA therapy outcomes are indicated. Support (If Any) National Institutes of Health: 1R01HL144859

Nasopharyngeal collapse can be identified on radiography in healthy male Beagle dogs without cardiopulmonary diseases.

Pharyngeal collapse has been described as a decrease of more than 50% in the diameter of the lumen. However, there has been no study on changes in the pharyngeal lumen in clinically normal dogs. The hypothesis of this prospective, observational, and pilot study was that change in nasopharyngeal lumen would be over 50% in Beagle dogs without cardiopulmonary diseases. Thus, we assessed the nasopharyngeal luminal change using cervical radiography in Beagle dogs without respiratory signs or cardiac abnormalities. The study sample included 42 Beagle dogs without cardiopulmonary diseases. Cervical radiographies were acquired during inspiration and expiration, and nasopharyngeal luminal change (%) was calculated. The median nasopharyngeal luminal change was 16.6%, and nasopharyngeal luminal change over 50% was identified in two dogs. The nasopharyngeal luminal change was significantly associated with body condition score and body weight. There was no correlation between nasopharyngeal luminal change and age. This study revealed that change in nasopharyngeal lumen over 50% can be identified in Beagle dogs without cardiopulmonary diseases and may be over-diagnosed as partial pharyngeal collapse. Further studies for comparing change in nasopharyngeal lumen between clinically normal dogs and dogs with respiratory signs are warranted.

Efficacy of atomoxetine plus oxybutynin in the treatment of obstructive sleep apnea with moderate pharyngeal collapsibility

PurposePreliminary studies have shown a significant decrease in severity of obstructive sleep apnea (OSA) with the use of a combination of atomoxetine and oxybutynin, with patients having moderate pharyngeal collapsibility during sleep more likely to respond. This study evaluated the efficacy and safety of AD036 (atomoxetine 80 mg and oxybutynin 5 mg) in the treatment of OSA.MethodsThis trial was a phase 2, randomized, placebo-controlled crossover study comparing AD036, atomoxetine 80 mg alone, and placebo during three home sleep studies, each separated by about 1 week. The trial included patients with OSA and moderate pharyngeal collapsibility as defined by a higher proportion of hypopneas to apneas and mild oxygen desaturation.ResultsOf 62 patients who were randomized, 60 were included in efficacy analyses. The apnea–hypopnea index (AHI) from a median (interquartile range) of 14.2 (5.4 to 22.3) events/h on placebo to 6.2 (2.8 to 13.6) with AD036 and 4.8 (1.4 to 11.6) with atomoxetine alone (p < .0001). Both drugs also decreased the oxygen desaturation index (ODI) and the hypoxic burden (p < .0001). AD036, but not atomoxetine alone, reduced the respiratory arousal index and improved ventilation at the respiratory arousal threshold (greater Vactive). There was a trend for total sleep time to be decreased more with atomoxetine alone than with AD036. The most common adverse event was insomnia (12% with AD036, 18% with atomoxetine).ConclusionAD036 significantly improved OSA severity in patients with moderate pharyngeal collapsibility. Atomoxetine may account for the majority of improvement in OSA severity, while the addition of oxybutynin may mitigate the disruptive effect of atomoxetine on sleep and further improve ventilation.Trial registrationClinical trial registered with www.clinicaltrials.gov (NCT04445688).

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship.

Purpose of ReviewObstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.Recent FindingsMild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.SummaryOSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Clinical polysomnographic methods for estimating pharyngeal collapsibility in obstructive sleep apnea.

Obstructive sleep apnea has major health consequences but is challenging to treat. For many therapies, efficacy is determined by the severity of underlying pharyngeal collapsibility, yet there is no accepted clinical means to measure it. Here, we provide insight into which polysomnographic surrogate measures of collapsibility are valid, applicable across the population, and predictive of therapeutic outcomes. Seven promising polysomnography-derived surrogate collapsibility candidates were evaluated: Vpassive (flow at eupneic ventilatory drive), Vmin (ventilation at nadir drive), event depth (depth of the average respiratory event), oxygen desaturation slope and mean oxygen desaturation (events-related averages), Fhypopneas (fraction of events scored as hypopneas), and apnea index. Evaluation included (1) validation by comparison to physiological gold-standard collapsibility values (critical closing pressure, Pcrit), (2) capacity to detect increased collapsibility with older age, male sex, and obesity in a large community-based cohort (Multi-Ethnic Study of Atherosclerosis, MESA), and (3) prediction of treatment efficacy (oral appliances and pharmacological pharyngeal muscle stimulation using atomoxetine-plus-oxybutynin). Pcrit was significantly correlated with Vmin (r = -0.54), event depth (r = 0.49), Vpassive (r = -0.38), Fhypopneas (r = -0.46), and apnea index (r = -0.46; all p < .01) but not others. All measures detected greater collapsibility with male sex, age, and obesity, except Fhypopneas and apnea index which were not associated with obesity. Fhypopneas and apnea index were associated with oral appliance and atomoxetine-plus-oxybutynin efficacy (both p < .05). Among several candidates, event depth, Fhypopneas, and apnea index were identified as preferred pharyngeal collapsibility surrogates for use in the clinical arena.

Critical to Know Pcrit: A Review on Pharyngeal Critical Closing Pressure in Obstructive Sleep Apnea.

It is crucial to understand the underlying pathophysiology of obstructive sleep apnea (OSA). Upper airway collapsibility is an important pathophysiological factor that affects the upper airway in OSA. The aim of the current study was to review the existing body of knowledge on the pharyngeal collapsibility in OSA. After a thorough search through Medline, PubMed, Scopus, and Web of science, the relevant articles were found and used in this study. Critical closing pressure (Pcrit) is the gold standard measure for the degree of collapsibility of the pharyngeal airway. Various physiological factors and treatments affect upper airway collapsibility. Recently, it has been shown that the baseline value of Pcrit is helpful in the upfront selection of therapy options. The standard techniques to measure Pcrit are labor-intensive and time-consuming. Therefore, despite the importance of Pcrit, it is not routinely measured in clinical practice. New emerging surrogates, such as finite element (FE) modeling or the use of peak inspiratory flow measurements during a routine overnight polysomnography, may enable clinicians to have an estimate of the pharyngeal collapsibility. However, validation of these techniques is needed.

Endocrine disorders in obstructive sleep apnoea syndrome: A bidirectional relationship.

Obstructive sleep apnoea (OSA) is a common disorder characterized by recurrent episodes of apnoea or hypopnea due to total or partial pharyngeal collapse and temporary upper airway obstruction during sleep. The prevalence of OSA is increasing and currently affects about 30% of men and 13% of women in Europe. Intermittent hypoxia, oxidative stress, systemic inflammation, and sleep fragmentation resulting from OSA can provoke subsequent cardiometabolic disorders. The relationships between endocrine disorders and OSA are complex and bidirectional. Indeed, several endocrine disorders are risk factors for OSA. Compared with the general population, the prevalence of OSA is increased in patients with obesity, hypothyroidism, acromegaly, Cushing syndrome, and type 1 and 2 diabetes. In some cases, treatment of the underlying endocrine disorder can improve, and occasionally cure, OSA. On the other hand, OSA can also induce endocrine disorders, particularly glucose metabolism abnormalities. Whether continuous positive airway pressure (CPAP) treatment for OSA can improve these endocrine disturbances remains unclear due to the presence of several confounding factors. In this review, we discuss the current state-of-the-art based on the review of the current medical literature for key articles focusing on the bidirectional relationship between endocrine disorders and OSA and the effects of treatment. Screening of OSA in endocrine patients is also discussed, as it remains a subject of debate.

No-cutting remodelling intra-pharyngeal surgery can avoid CPAP in selected OSA patients: myth or reality?

Oropharyngeal surgery for Obstructive Sleep Apnea (OSA) has evolved from a radical excision of "redundant" soft tissue for the enlargment of the airway to a minimally invasive reconstruction to fulfill both preservation of pharyngeal function and improvement of sleep apnea. Recently, Alianza surgical technique has been successfully introduced as a new, non-resective procedure aimed to treat concentric pharyngeal collapse at the velum using Barbed Sutures. The aim of this study was to show the effectiveness and safety of Alianza technique as standalone surgical treatment in selected patients with moderate-severe OSA and concentric pharyngeal collapse that refused or did not tolerate Continuous Positive Airway Pressure therapy. Effectiveness of the surgical procedure was assessed by means of the Epworth Sleepiness Scale (ESS), Home Sleep Test, and a 0-10 snoring VAS. At the end of our selection process, 26 patients were enrolled, with a mean age of 52.7 ± 9.2years, that undergone Alianza tecnique. There was a statistically significant reduction in mean post-operative apnea-hypopnea indexes (34.1 ± 11.5-16.3 ± 10.3; p <0.01), mean oxygen desaturation index (29.0 ± 14.5-13.1 ± 9.2; p < 0.01), and mean ESS scores (12.1 ± 5.8 and 5.8 ± 4.4; p < 0.01).There was also a significant decrease in mean post-operative snoring VAS scores (7.85 ± 1.23 vs 3.2 ± 1.7, p < 0.01). There were no major complications. Our preliminary results suggest that Alianza technique is a safe and repeatable surgery. Further studies on a larger scale are needed to confirm these encouraging data supporting the role of Alianza alone or in OSA multilevel surgery in selected OSA patients.

Optimal application of soft-palate webbing flap pharyngoplasty combined with nasal surgery for surgical treatment of primary snoring and obstructive sleep apnea

BackgroundExcessive collapse of the soft palate and lateral pharyngeal wall narrowing are established causes of loud snoring and sleep apnea in subjects with obstructive sleep apnea (OSA). Therefore, delicate surgical techniques are needed to reshape the soft palate and create sufficient tension in the lateral pharyngeal wall. This study aimed to determine the therapeutic outcome and favorable indications of soft-palate webbing flap pharyngoplasty in subjects with OSA and primary snoring.MethodsA total of 174 subjects who underwent soft-palate webbing flap pharyngoplasty combined with uvulopalatal flap and septoturbinoplasty from August 2015 to February 2020 were included in this study. Medical records, including pre- and postoperative sleep parameters, were retrospectively reviewed. The primary outcome measure was the degree of improvement in AHI after surgery. Other outcomes were differences in surgical response rates, subjective visual analog score (VAS) for snoring, sleep quality, and complications.ResultsPolysomnographic results showed that apnea–hypopnea index (AHI) scores were significantly reduced from 39.6 ± 6.1 to 22.9 ± 3.6 following soft-palate webbing flap pharyngoplasty in 59 subjects, and overall success and response rates of this technique were analyzed with 71%. We found that the successful outcomes were observed in 50% of mild (n = 12) and 56% of moderate (n = 16) subjects with OSA subjects due to lateral pharyngeal wall collapse. The success rate of soft-palate webbing flap pharyngoplasty was relatively higher in subjects with mild and moderate OSA than those with severe OSA. Additionally, the mean VAS snoring scale was 4.7 and subjects’ primary snoring intensity significantly improved to 2.9 after soft-palate webbing flap pharyngoplasty. Subjective symptoms such as daytime sleepiness and sleep quality also showed improvement. Most complications were found to be minimal and improved by 1 month after the operation.ConclusionOur data demonstrate that soft-palate webbing flap pharyngoplasty is an effective treatment for OSA and primary snoring and may be a promising technique to reduce lateral pharyngeal wall collapse.

Critical closing pressure of the pharyngeal airway during routine drug-induced sleep endoscopy: feasibility and protocol.

In obstructive sleep apnea (OSA), there are various pathophysiological factors affecting the upper airway during sleep. Two prominent factors contributing to OSA are site and pattern of upper airway collapse and degree of pharyngeal collapsibility. In a clinical setting, drug-induced sleep endoscopy (DISE) is used to visualize the structures of the upper airway. Critical closing pressure (Pcrit) is the gold standard measure of pharyngeal collapsibility. This prospective clinical study aimed to investigate the feasibility and protocol of Pcrit measurements during DISE. Thirteen patients with OSA were included. Pcrit was calculated using peak inspiratory airflow and inspiratory ventilation. The proposed protocol was successful in Pcrit measurement during DISE in all subjects [median[Q1;Q3] Pcrit for "peak inspiratory method" (n = 12): -0.84[-2.07;0.69] cmH2O, "ventilation method" (n = 13): -1.32[2.32;0.47] cmH2O], highlighting the feasibility of the approach. There was no significant difference (P = 0.67) between calculated Pcrit with either of the calculation methods, indicating high reliability. Correlation analysis showed Pcrit as an independent parameter of any of the anthropometric or polysomnographic parameters. The ventilation method proved to be more successful in assessment of Pcrit in subjects with epiglottic collapse (e.g., with high negative effort dependence). Subjects with palatal complete concentric collapse during DISE had a wide Pcrit range ([-2.86;2.51]cmH2O), suggesting no close correlation between Pcrit and this DISE pattern (P = 0.38). Incorporation of Pcrit measurements into DISE assessments is feasible and may yield valuable additional information for OSA management. Combining Pcrit and DISE provides information on both the site and degree of upper airway collapse and the degree of pharyngeal collapsibility.NEW & NOTEWORTHY The protocol of this study was successful in concomitant measurement of Pcrit during routine clinical endoscopy. Comparison of two calculation methods for Pcrit showed that the inspiratory ventilation method was more successful in assessment of Pcrit in subjects with epiglottic collapse who have high negative effort dependence. Subjects with palatal complete concentric collapse during DISE had a wide Pcrit range and did not have a greater Pcrit than patients in other site of collapse categories.

Implications of Obstructive Sleep-related Breathing Disorder in Dentistry: Focus on Snoring and Obstructive Sleep Apnea.

Obstructive sleep-related breathing disorder (SRBD) is an umbrella term that encompasses various types of upper airway dysfunctions during sleep characterized by increased respiratory effort secondary to snoring and/or increased upper airway resistance and pharyngeal collapse. Obstructive sleep apnea (OSA) is a representative SRBD that involves a significant decrease in or cessation of airflow despite the presence of respiratory effort. While snoring is considered a normal condition, it can cause serious noise disturbance to sleep partners and is considered a predictor of OSA. Snoring and OSA are highly correlated with obesity. SRBDs can lead to cardiovascular disease, hypertension, decreased quality of life, decreased work efficiency, daytime sleepiness, decreased neurocognitive activity, and psychological impairments. In dentistry, research on sleep problems has focused on temporomandibular disorder (TMD)/orofacial pain. The relationship between OSA and TMD/orofacial pain has been reported, but it is not clear whether it is a simple correlation or a causal relationship. Therefore, we aimed to review the causes of SRBDs including snoring and OSA and to review and infer the relationship between these SRBDs and TMD/orofacial pain. The effects of snoring and OSA extend beyond sleep disturbances and are worthy of future research, especially with regard to TMD.

Sleep apnoea and heart failure

Heart failure and sleep disordered breathing (SDB) are two common conditions that frequently overlap and have been studied extensively in the past three decades. Obstructive sleep apnoea (OSA) may result in myocardial damage due to intermittent hypoxia that leads to increased sympathetic activity and transmural pressures, low-grade vascular inflammation, and oxidative stress. On the other hand, central sleep apnoea and Cheyne-Stokes respiration (CSA-CSR) occurs in heart failure, irrespective of ejection fraction, either reduced (HFrEF), preserved (HFpEF) or mildly reduced (HFmrEF). The pathophysiology of CSA-CSR relies on several mechanisms leading to hyperventilation, breathing cessation and periodic breathing. Pharyngeal collapse may result at least in part from fluid accumulation in the neck, owing to daytime fluid retention and overnight rostral fluid shift from the legs. Although both OSA and CSA-CSR occur in heart failure, the symptoms are less suggestive than in typical (non-heart failure-related) OSA. Overnight monitoring is mandatory for a proper diagnosis, with accurate measurement and scoring of central and obstructive events, since the management will be different depending on whether the sleep apnoea in heart failure is predominantly OSA or CSA-CSR. SDB in heart failure is associated with worse prognosis, including higher mortality, than in patients with heart failure but without SDB. However, there is currently no evidence that treating SDB improves clinically important outcomes in patients with heart failure, such as cardiovascular morbidity and mortality.