Efficacy of Maxillomandibular Advancement Examined with Drug-Induced Sleep Endoscopy and Computational Fluid Dynamics Airflow Modeling

Combination Tonsillectomy and Hypoglossal Nerve Stimulation for Sleep Apnea Patients With Oropharyngeal Lateral Wall Collapse

OBJECTIVE

The efficacy of hypoglossal nerve stimulation (HGNS) therapy is limited by obstruction of the oropharyngeal lateral walls (OLWs). Our objective was to investigate the effect of palatine tonsillectomy on HGNS efficacy in obstructive sleep apnea (OSA) patients with OLW collapse.

STUDY DESIGN

Case-control study of patients with moderate-to-severe OSA, complete-or-partial OLW collapse, and small tonsils (1 - 2+). Concomitant palatine tonsillectomy and HGNS (HGNS+T) were compared against a control group of patients who underwent HGNS alone.

SETTING

Single academic institution.

METHODS

Study outcomes were measures of HGNS efficacy defined as a %reduction in apnea-hypopnea index (AHI) (primary) and successful treatment response (50% AHI reduction to <15/h, logistic regression), respectively. Regression analyses quantified the additional effect of tonsillectomy (HGNS+T vs HGNS alone, independent variable) on HGNS efficacy. Analyses were adjusted for OLW collapse severity (complete vs partial), tonsil size, age, sex, body mass index, and baseline AHI.

RESULTS

Nineteen patients underwent HGNS+T and had follow-up sleep testing for the current analysis. The control group (HGNS alone) consisted of 78 patients. Baseline demographics and OSA severity were similar between the groups, except HGNS+T group had increased prevalence of complete OLW collapse. Linear regression demonstrated that adding tonsillectomy resulted in an additional 22.9% [7.5, 35.2] reduction in AHI [95% confidence interval, CI] (P = .006), and 8.6 [1.7,43.4] (P = .010) greater odds [95% CI] of a successful treatment response with HGNS.

CONCLUSION

Compared to historically poorer outcomes of HGNS in patients with OLW collapse, these early results suggest combining tonsillectomy with HGNS may represent a promising strategy to improve success rates.

Non-sleep related outcomes of maxillomandibular advancement, a systematic review

Maxillomandibular advancement has been shown to be an effective treatment for obstructive sleep apnea; however, the literature focuses mainly on sleep-related parameters such as apnea-hypopnea index, respiratory disturbance index and Epworth sleepiness scale. Other factors that may be important to patients, such as esthetics, patient satisfaction, nasality, swallowing problems and so forth have been reported in the literature but have not been systematically studied. Together with an information specialist, an extensive search in Medline, Embase and Scopus yielded 1592 unique articles. Titles and abstracts were screened by two blinded reviewers. In total, 75 articles were deemed eligible for full-text screening and 38 articles were included for qualitative synthesis. The most common categories of non-sleep related outcomes found were surgical accuracy, facial esthetics, functional outcomes, quality of life, patient satisfaction, and emotional health. All categories were reported using heterogenous methods, such that meta-analysis could not be performed. There was lack of consistent methods to assess these outcomes. This work is the first to systematically review non-sleep related outcomes of maxillomandibular advancement. Despite growing interest in evaluating surgical outcomes through patient subjective experiences, this review points to the need of standardized, validated methods to report these outcomes.

Chronic Rhinosinusitis After Maxillary Advancement Orthognathic Surgery

INTRODUCTION

Maxillomandibular advancement (MMA) remains an effective procedure for the management of obstructive sleep apnea (OSA). Maxillary advancement may lead to anatomical changes that impair paranasal sinus drainage, leading to chronic sinus inflammation. The aim of this study was to describe the clinical features and outcomes of patients suffering from chronic rhinosinusitis (CRS) following MMA.

METHODS

This is a retrospective case series study. Our study included subjects diagnosed with CRS following MMA from January 1992 to October 2018 at Stanford Hospital. We screened 730 patients undergoing MMA and identified a total of 57 with CRS after MMA. A descriptive analysis was performed using clinical data including patient demographics, comorbidities, prior surgical history, physical exam manifestations, CT findings, and quality of life outcomes (SNOT-22).

RESULTS

Out of 730 patients undergoing MMA, 57(7.8%) were found to have CRS after orthognathic surgery. Presenting symptoms included facial pain (92.5%), nasal drainage (75%), nasal obstruction (67.5%), and hyposmia (20%). Endoscopic examination revealed recirculation (30.5%), purulent discharge (27.7%), polypoid changes (22.2%), and scarring (13.8%). Preoperative CT prior to undergoing endoscopic sinus surgery (ESS) demonstrated mucosal thickening in maxillary (64.2%), anterior ethmoid (39.2%), frontal (14.2%), posterior ethmoid (10.7%), sphenoid sinus (14.2%), and ostiomeatal complex (55.3%). Average Lund-Mackay score was 5.5(±3.8). Additional CT findings included secondary ostium in the inferior meatus (42.8%). Forty patients (70.1%) underwent ESS at a mean of 4.6 years after MMA. Patients undergoing ESS experienced significant improvement in SNOT-22 scores at 12-months post-surgery (P = .018).

CONCLUSION

Patients undergoing maxillary advancement surgery are at risk of developing CRS postoperatively and should be advised of the risk of CRS associated with this procedure. Surgical treatment can be an option for medically refractory CRS related to MMA surgery.

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

Background

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

Methods

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

Results

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

Conclusion

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

Supplementary Information

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

The relationship between aerodynamic characteristics of the upper airway and severity of obstructive sleep apnea in adults

OBJECTIVE

To investigate the relationship between aerodynamic characteristics of the upper airway and severity of obstructive sleep apnea (OSA) in adults.

METHODS

Ninety-seven adult OSA patients underwent polysomnography and cone beam computed tomography (CBCT). The anatomical and aerodynamic characteristics were measured based on CBCT images and computational fluid dynamics modelling of the upper airway.

RESULTS

After controlling for patients' gender, age, and body mass index (BMI), the maximum velocity during inspiration (In-Vmax) led to the largest increase in the explanatory power of apnea-hypopnea index (AHI) variation. The In-Vmax was closely correlated with the minimum axial area, and their relationship was represented by an inversely proportional fitted curve.

CONCLUSIONS

The In-Vmax was the most relevant to OSA severity, and it could be used to assist in recognizing severe OSA patients and as a primary variable to evaluate treatment outcomes of OSA. The In-Vmax was closely related to the most constricted area of the upper airway.

Maxillomandibular advancement for obstructive sleep apnea: a retrospective prognostic factor study for surgical response

PURPOSE

To identify potential predictors of surgical response to maxillomandibular advancement (MMA) in patients with obstructive sleep apnea (OSA) from the most common clinically available data (patient-related, polysomnographic, cephalometric, and surgical variables).

METHODS

This was a retrospective study comprised of consecutive patients who underwent MMA for moderate to severe OSA. Relevant clinical, polysomnographic, cephalometric, and surgical variables were collected as independent variables (predictors). The association of the independent variables with a favorable surgical response to MMA was assessed in univariate and multivariate analyses.

RESULTS

In 100 patients (82% male; mean age 50.5 years), the mean apnea hypopnea index [AHI] was 53.1 events/h. The rate of favorable surgical response was 67%. Based on multivariate analysis, patients with cardiovascular disease (CVD) had 0.140 times lower odds of a favorable response to MMA (OR: 0.140 [0.038, 0.513], P = 0.003). For each 1-unit increase in central apnea index (CAI) and superior posterior airway space (SPAS), there were 0.828 and 0.724 times lower odds to respond favorably to MMA (OR: 0.828 [0.687, 0.997], P = 0.047; and 0.724 [0.576, 0.910], P = 0.006), respectively.

CONCLUSION

The findings of this study suggest that the surgical outcome of MMA may be less favorable when patients with OSA have certain phenotypic characteristics: the presence of CVD, higher CAI and larger SPAS. If confirmed in future studies, these variables may guide patient selection for MMA.

Association of Backscattered Ultrasonographic Imaging of the Tongue With Severity of Obstructive Sleep Apnea in Adults

Importance

Determining interventions to manage obstructive sleep apnea (OSA) depends on clinical examination, polysomnography (PSG) results, and imaging analysis. There remains the need of a noninvasive and cost-effective way to correlate relevant upper airway anatomy with severity of OSA to direct treatment and optimize outcome.

Objective

To determine whether backscattered ultrasonographic imaging (BUI) analysis of the tongue is associated with severity of OSA in adults.

Design, Setting, and Participants

In this prospective, single-center, diagnostic study of a consecutive series of patients (aged ≥18 years) at a sleep surgery clinic, the 89 included patients had a PSG within 3 years at the time of ultrasonography and BUI analysis between July 2020 and March 2022. Patients were excluded if body mass index had changed more than 10% since time of PSG. A standardized submental ultrasonographic scan with laser alignment was used with B-mode and BUI analysis applied to the tongue. The B-mode and BUI intensity were associated with the apnea-hypopnea index (AHI), a measure of severity of apnea from normal (no OSA) to severe OSA.

Exposures

Ultrasonography and PSG.

Main Outcomes and Measures

The main outcomes were BUI parameters and their association with AHI value.

Results

Eighty-nine patients were included between July 2020 and March 2022. A total of 70 (78.7%) male patients were included; and distribution by race and ethnicity was 46 (52%) White participants, 22 (25%) Asian participants, and 2 (2%) African American participants, and 19 (21%) others. Median (IQR) age was 37.0 (29.0-48.3) years; median (IQR) BMI was 25.3 (23.2-29.8); and median (IQR) AHI was 11.1 (5.6-23.1) events per hour. At the middle to posterior tongue region, the 4 OSA severity levels explained a significant portion of the BUI variance (η2 = 0.153-0.236), and a significant difference in BUI values was found between the subgroups with AHI values of less than 15 (no OSA and mild OSA) and greater than or equal to 15 (moderate OSA and severe OSA) events per hour. The echo intensity showed no significant differences. The BUI values showed a positive association with AHI, with a Spearman correlation coefficient of up to 0.43. Higher BUI values remained associated with higher AHI after correction for the covariates of BMI and age.

Conclusions and Relevance

In this prospective diagnostic study, standardized BUI analysis of the tongue was associated with OSA severity. With the practicality of ultrasonography, this analysis is pivotal in connecting anatomy with physiology in treatment planning for patients with OSA.

Effects of maxillomandibular advancement on respiratory function and facial aesthetics in obstructive sleep apnoea patients with versus without maxillomandibular deficiency

The aim of this study was to compare the effects of maxillomandibular advancement (MMA) on respiratory function between obstructive sleep apnoea (OSA) patients with and without maxillomandibular deficiency, and to compare the changes in facial aesthetics after MMA between the two groups. MMA-treated patients who had both baseline and follow-up polysomnography (PSG) data and lateral cephalograms were enrolled in this retrospective study. In addition to PSG and cephalometric data, patient satisfaction with postoperative breathing and facial aesthetics, and overall satisfaction with the treatment were assessed. Twenty-one patients were classified as not having maxillomandibular deficiency (without-deficiency group) and 40 patients as having maxillomandibular deficiency (with-deficiency group). The improvements in respiratory parameters (e.g., apnoea-hypopnoea index) and patient satisfaction with postoperative breathing were comparable in the two groups (P = 0.094-0.713). The changes in facial profile measurements (e.g., nasal prominence, nasolabial angel, and lip positions relative to the true vertical line) and patient satisfaction with postoperative facial aesthetics were also comparable in the two groups (P = 0.148-0.983). In conclusion, no significant difference in the effects of MMA on respiratory function and facial aesthetics between OSA patients with and without maxillomandibular deficiency was observed.

Value of Surgical and Nonsurgical Treatment for Sleep Apnea: A Closer Look at Healthcare Utilization

OBJECTIVE

To determine how surgery, continuous positive airway pressure (CPAP), and no treatment impact healthcare utilization in patients who have obstructive sleep apnea (OSA).

STUDY DESIGN

This is a retrospective cohort study of patients between the ages of 18 and 65 that were diagnosed with OSA (9th International Classification of Diseases) from January 2007 to December 2015. Data were collected over 2 years, and prediction models were generated to evaluate trends over time.

SETTING

A population-based study using real-world data and insurance databases.

METHODS

A total of 4,978,649 participants were identified, all with at least 25 months of continuous enrollment. Patients with previous soft tissue procedures not approved for OSA (nasal surgery), or without continuous insurance coverage were excluded. A total of 18,050 patients underwent surgery, 1,054,578 were untreated, and 799,370 received CPAP. IBM Marketscan Research database was utilized to describe patient-specific clinical utilization, and expenditures, across outpatient, and inpatient services, and medication prescriptions.

RESULTS

When the cost of the intervention was eliminated in the 2-year follow-up, the monthly payments of group 1 (surgery) were significantly less than group 3 (CPAP) in overall, inpatient, outpatient, and pharmaceutical payments (p < .001). The surgery group was associated with less cumulative payments compared to the other 2 groups when the cost of the intervention (CPAP or surgery) was eliminated in all comorbidities and age groups.

CONCLUSION

Treating OSA with surgery can lessen overall healthcare utilization compared to no treatment and CPAP.

Automatic scoring of drug-induced sleep endoscopy for obstructive sleep apnea using deep learning

BACKGROUND

Treatment of obstructive sleep apnea is crucial for long term health and reduced economic burden. For those considered for surgery, drug-induced sleep endoscopy (DISE) is a method to characterize location and pattern of sleep-related upper airway collapse. According to the VOTE classification system, four upper airway sites of collapse are characterized: velum (V), oropharynx (O), tongue (T), and epiglottis (E). The degree of obstruction per site is classified as 0 (no obstruction), 1 (partial obstruction), or 2 (complete obstruction). Here we propose a deep learning approach for automatic scoring of VOTE obstruction degrees from DISE videos.

METHODS

We included 281 DISE videos with varying durations (6 s-16 min) from two sleep clinics: Copenhagen University Hospital and Stanford University Hospital. Examinations were split into 5-s clips, each receiving annotations of 0, 1, 2, or X (site not visible) for each site (V, O, T, and E), which was used to train a deep learning model. Predicted VOTE obstruction degrees per examination was obtained by taking the highest predicted degree per site across 5-s clips, which was evaluated against VOTE degrees annotated by surgeons.

RESULTS

Mean F1 score of 70% was obtained across all DISE examinations (V: 85%, O: 72%, T: 57%, E: 65%). For each site, sensitivity was highest for degree 2 and lowest for degree 0. No bias in performance was observed between videos from different clinicians/hospitals.

CONCLUSIONS

This study demonstrates that automating scoring of DISE examinations show high validity and feasibility in degree of upper airway collapse.

Maxillomandibular Advancement and Upper Airway Stimulation for Treatment of Obstructive Sleep Apnea: A Systematic Review

This systematic review aimed to comparatively evaluate the efficacy and safety of maxillomandibular advancement (MMA) and upper airway stimulation (UAS) in obstructive sleep apnea (OSA) treatment. A MEDLINE and Embase database search of articles on MMA and/or UAS for OSA was conducted. Twenty-one MMA studies and nine UAS studies were included. All the MMA studies demonstrated a reduction in apnea hypopnea index (AHI) postoperatively, and success rates ranged from 41.1% to 100%. Ten MMA studies reported pre- and postoperative Epworth sleepiness scale (ESS), and all but one study demonstrated a reduction in ESS. In the UAS studies, all but one demonstrated a reduction in AHI, and success rates ranged from 26.7% to 77.8%. In the eight UAS studies reporting pre- and postoperative ESS, an ESS reduction was demonstrated. No studies reported any deaths related to MMA or UAS. The most common postoperative complications after MMA and UAS were facial paresthesia in the mandibular area and discomfort due to electrical stimulation, respectively. This systematic review suggests that both MMA and UAS are effective and generally safe therapies for OSA. However, due to the limitations of the included studies, there is no evidence yet to directly compare these two procedures in OSA treatment.

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

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

Current and Novel Treatment Options for OSA

Obstructive sleep apnoea is a challenging medical problem due to its prevalence, its impact on quality of life and performance in school and professionally, the implications for risk of accidents, and comorbidities and mortality. Current research has carved out a broad spectrum of clinical phenotypes and defined major pathophysiological components. These findings point to the concept of personalised therapy, oriented on both the distinct clinical presentation and the most relevant pathophysiology in the individual patient. This leads to questions of whether sufficient therapeutic options other than positive airway pressure (PAP) alone are available, for which patients they may be useful, if there are specific indications for single or combined treatment, and whether there is solid scientific evidence for recommendations. This review describes our knowledge on PAP and non-PAP therapies to address upper airway collapsibility, muscle responsiveness, arousability and respiratory drive. The spectrum is broad and heterogeneous, including technical and pharmaceutical options already in clinical use or at an advanced experimental stage. Although there is an obvious need for more research on single or combined therapies, the available data demonstrate the variety of effective options, which should replace the unidirectional focus on PAP therapy.

The analysis of individual pathophysiological composition opens new directions towards personalised treatment of OSA, focusing not only on pharyngeal dilation, but also on technical or pharmaceutical interventions on muscle function or breathing regulationhttps://bit.ly/3sayhkd

Evaluation of drug-induced sleep endoscopy as a tool for selecting patients with obstructive sleep apnea for maxillomandibular advancement

STUDY OBJECTIVES

(1) To investigate if drug-induced sleep endoscopy (DISE) findings are predictive of surgical response for patients undergoing maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) and (2) to investigate the predictive value of the jaw thrust maneuver during DISE in terms of surgical response to MMA.

METHODS

A retrospective cohort study was conducted in patients with OSA who underwent a baseline polysomnography (PSG) and DISE followed by MMA and a 3- to 6-month follow-up PSG between September 1, 2011, and September 30, 2020.

RESULTS

Sixty-four patients with OSA (50 males [78.1%]; mean ± SD age = 51.7 ± 9.5 years; mean ± SD apnea-hypopnea index = 49.0 ± 20.8 events/h) were included. Thirty-nine patients were responders, and 25 were nonresponders. Adjusting for baseline characteristics and surgical characteristics (eg, age, baseline apnea-hypopnea index, degree of maxillary advancement), patients with complete anteroposterior epiglottic collapse had 0.239 times lower odds for response to MMA (95% confidence interval, 0.059-0.979; P = .047). No significant relationship was found between complete concentric velum collapse and MMA response. There was no statistically significant association between effect of jaw thrust maneuver during DISE on upper airway patency and treatment outcome of MMA.

CONCLUSIONS

This study indicates that DISE is a promising tool to identify patients who will or will not respond to MMA for treating OSA. Patients with complete anteroposterior epiglottic collapse may be less suitable candidates for MMA.

CITATION

Zhou N, Ho J-PTF, de Vries N, Bosschieter PFN, Ravesloot MJL, de Lange J. Evaluation of drug-induced sleep endoscopy as a tool for selecting patients with obstructive sleep apnea for maxillomandibular advancement. J Clin Sleep Med. 2022;18(4):1073-1081.

Prevention of Incident Hypertension in Patients With Obstructive Sleep Apnea Treated With Uvulopalatopharyngoplasty or Continuous Positive Airway Pressure: A Cohort Study

Purpose

To determine whether treatment with uvulopalatopharyngoplasty (UPPP) or continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) prevents hypertension, compared to those not receiving any treatment.

Methods

A retrospective cohort study was conducted among 413 patients with OSA (age ≥ 35 years) at the Shuang Ho Hospital between 2009 and 2016. The patients were divided into three groups: UPPP, CPAP, and non-treatment groups. Data about the personal characteristics, history of comorbidities, and polysomnography (PSG) reports were collected at baseline. A Cox model with inverse probability of treatment weighting was used to adjust for confounders and baseline diversity.

Results

After multivariate adjustment and weighting for incident hypertension, patients in both the CPAP and UPPP groups showed a significant preventive effect on hypertension than in the non-treatment group. Moreover, patients in the CPAP group had lower event rates than those in the UPPP group.

Conclusion

UPPP can prevent the development of new-onset hypertension in patients with OSA. CPAP had a better preventive effect than UPPP. UPPP might be a good alternative for reducing the risk of the onset of hypertension when compliance to CPAP is poor.

Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

INTRODUCTION

This systematic review provides supporting evidence for the accompanying clinical practice guideline on the referral of adults with obstructive sleep apnea (OSA) for surgical consultation.

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of upper airway sleep apnea surgery or bariatric surgery to no treatment as well as studies that reported on patient-important and physiologic outcomes pre- and postoperatively. Statistical analyses were performed to determine the clinical significance of using surgery to treat obstructive sleep apnea in adults. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 274 studies that provided data suitable for statistical analyses. The analyses demonstrated that surgery as a rescue therapy results in a clinically significant reduction in excessive sleepiness, snoring, blood pressure (BP), apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and oxygen desaturation index (ODI); an increase in lowest oxygen saturation (LSAT) and sleep quality; and an improvement in quality of life in adults with OSA who are intolerant or unaccepting of positive airway pressure (PAP) therapy. The analyses demonstrated that surgery as an adjunctive therapy results in a clinically significant reduction in optimal PAP pressure and improvement in PAP adherence in adults with OSA who are intolerant or unaccepting of PAP due to side effects associated with high pressure requirements. The analyses also demonstrated that surgery as an initial treatment results in a clinically significant reduction in AHI/RDI, sleepiness, snoring, BP, and ODI and an increase in LSAT in adults with OSA and major anatomical obstruction. Analysis of bariatric surgery data showed a clinically significant reduction in BP, AHI/RDI, sleepiness, snoring, optimal PAP level, BMI, and ODI and an increase in LSAT in adults with OSA and obesity. Analyses of very limited evidence suggested that upper airway surgery does not result in a clinically significant increase in risk of serious persistent adverse events and suggested that bariatric surgery may result in a clinically significant risk of iron malabsorption that may be managed with iron supplements. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(12):2507-2531.

A Comprehensive Strategy for Improving Nasal Outcomes After Large Maxillomandibular Advancement for Obstructive Sleep Apnea

Background: Rate of corrective nasal surgery after maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) has been reported to be 18.7% for functional and aesthetic indications. Objective: Describe a comprehensive strategy to optimize nasal outcomes with MMA for OSA. Methods: A retrospective review of patients undergoing MMA for OSA in a tertiary referral center was performed, with a comprehensive perioperative intervention to optimize nasal outcomes from January 2014 to February 2018. Outcomes included the Apnea-Hypopnea Index (AHI), oxygen saturation (SpO₂) nadir, corrective nasal surgery needed after MMA, and Nasal Obstruction Symptom Evaluation (NOSE) scores. Results: AHI after MMA showed significant reduction (-34.65, p < 0.001), SpO₂ nadir increased (+6.08, p < 0.001), and NOSE scores decreased (-5.96, p < 0.001). Corrective nasal surgery needed after MMA was reported in 6.5% (8 of 122) subjects at a mean of 8.5 months, ranging from 1 to 24.7 months. Six subjects underwent either septoplasty and/or valve stenosis repair, and two subjects underwent functional and aesthetic rhinoplasty. Conclusion: A perioperative strategy was applied since 2014 that showed effectiveness in reducing post-MMA corrective nasal surgery to 6.5%.

Correlation between the transverse dimension of the maxilla, upper airway obstructive site, and OSA severity

STUDY OBJECTIVES

Acquiring a better comprehension of obstructive sleep apnea physiopathology can contribute to improving patient selection for surgical treatments. We hypothesize that maxillary transverse deficiency restricts the space available for the tongue, leading to upper airway obstruction during sleep. Our primary hypothesis was that maxillary transverse deficiency increases the prevalence of tongue collapse during drug-induced sleep endoscopy (DISE). The secondary hypothesis was that maxillary transverse deficiency will also increase the prevalence of circumferential collapse at the velopharynx. The exploratory hypothesis was that maxillary transverse deficiency is associated with increased obstructive sleep apnea severity. The objectives of this study were to correlate maxillary morphometric measurements with (1) the anatomic level of obstruction during DISE and (2) the apnea-hypopnea index on polysomnography.

METHODS

We made a cross-sectional analysis of patients with obstructive sleep apnea undergoing DISE in search of positive airway pressure alternative treatment. Maxillary measurements were collected from a computed tomography scan (interpremolar distance, intermolar distance [IMD] and sella-nasion A point angle), findings from DISE, and sleep study variables from polysomnography. Correlation between computed tomography, DISE, and polysomnography data was assessed using Pearson's correlation, and receiver operating characteristic curves were determined for each facial measurement.

RESULTS

Sixty-nine patients were included in the study. The group with velopharyngeal circumferential collapse had mean IMD = 26.30 mm (25.5-31.45), and the group with anteroposterior collapse had mean IMD = 29.20 mm (26.8-33.10; P = .040). The group with complete tongue-base obstruction had mean interpremolar distance = 26.40 mm (25.1-28) and IMD = 26.30 mm (25.6-28.4), and the group without obstruction had mean interpremolar distance = 28.7 mm (27.2-30; P = .003) and IMD = 34.06 mm (32.1-37; P < .001). The receiver operating characteristic curve determined an IMD cutoff of 29.8 mm for predicting tongue-base obstruction.

CONCLUSIONS

The maxillary transverse deficiency, identified by reduction in interpremolar distance and IMD, predicted the occurrence of complete tongue-base obstruction, complete concentric collapse at the velopharynx, and multilevel obstruction during DISE. We did not find an association between the maxillary measurements and obstructive sleep apnea severity. These associations hold some promise in ultimately supplanting insights previously available only through DISE.

OSA Upper Airways Surgery: A Targeted Approach

Obstructive sleep apnea syndrome (OSA) is a multi-factorial disorder, with quite complex endotypes, consisting of anatomical and non-anatomical pathophysiological factors. Continuous positive airway pressure (CPAP) is recognized as the first-line standard treatment for OSA, whereas upper airway (UA) surgery is often recommended for treating OSA patients who have refused or cannot tolerate CPAP. The main results achievable by the surgery are UA expansion, and/or stabilization, and/or removal of the obstructive tissue to different UA levels. The site and pattern of UA collapse identification is of upmost importance in selecting the customized surgical procedure to perform, as well as the identification of the relation between anatomical and non-anatomical factors in each patient. Medical history, sleep studies, clinical examination, UA endoscopy in awake and drug-induced sedation, and imaging help the otorhinolaryngologist in selecting the surgical candidate, identifying OSA patients with mild UA collapsibility or tissue UA obstruction, which allow achievement of the best surgical outcomes. Literature data reported that the latest palatal surgical procedures, such as expansion sphincter palatoplasty or barbed reposition palatoplasty, which achieve soft palatal and lateral pharyngeal wall remodeling and stiffening, improved the Apnea Hypopnea Index, but the outcome analyses are still limited by methodological bias and the limited number of patients' in each study. Otherwise, the latest literature data have also demonstrated the role of UA surgery in the improvement of non-anatomical factors, confirming that a multidisciplinary and multimodality diagnostic and therapeutical approach to OSA patients could allow the best selection of customized treatment options and outcomes.

Maxillomandibular advancement versus multilevel surgery for treatment of obstructive sleep apnea: A systematic review and meta-analysis

Multilevel surgery (MLS) and maxillomandibular advancement surgery (MMA) are two established options in surgical management of obstructive sleep apnea (OSA), which target different levels of airway obstruction. The objective of this review was to comparatively evaluate the clinical efficacy and safety of MMA and MLS in the treatment of OSA. MEDLINE and Embase databases were searched for studies on MMA and/or MLS in OSA patients. Twenty MMA studies and 39 MLS studies were identified. OSA patients who underwent MMA showed significant improvements in AHI, LSAT, ODI, and ESS by -46.2/h, 13.5%, -30.3/h, and -8.5, respectively. The pooled rates of surgical success and cure for MMA were 85.0% and 46.3%, respectively. Patients who underwent MLS showed significant improvements in AHI, LSAT, ODI, and ESS by -24.7/h, 8.7%, -19.1/h, and -5.8, respectively. The pooled surgical success and cure rates for MLS were 65.1% and 28.1%, respectively. The rates of major complication of MMA and MLS were 3.2% and 1.1%, respectively, and the rate of minor complication of MMA was higher than that of MLS. We conclude that both MMA and MLS are effective treatment options for OSA. Compared to MLS, MMA may be more effective in improving OSA. However, the complication rate of MMA is higher.

Detailed evaluation of the upper airway in the Dp(16)1Yey mouse model of Down syndrome

A high prevalence of obstructive sleep apnea (OSA) has been reported in Down syndrome (DS) owing to the coexistence of multiple predisposing factors related to its genetic abnormality, posing a challenge for the management of OSA. We hypothesized that DS mice recapitulate craniofacial abnormalities and upper airway obstruction of human DS and can serve as an experimental platform for OSA research. This study, thus, aimed to quantitatively characterize the upper airway as well as craniofacial abnormalities in Dp(16)1Yey (Dp16) mice. Dp16 mice demonstrated craniofacial hypoplasia, especially in the ventral part of the skull and the mandible, and rostrally positioned hyoid. These changes were accompanied with a shorter length and smaller cross-sectional area of the upper airway, resulting in a significantly reduced upper airway volume in Dp16 mice. Our non-invasive approach, a combination of computational fluid dynamics and high-resolution micro-CT imaging, revealed a higher negative pressure inside the airway of Dp16 mice compared to wild-type littermates, showing the potential risk of upper airway collapse. Our study indicated that Dp16 mice can be a useful model to examine the pathophysiology of increased upper airway collapsibility of DS and to evaluate the efficacy of therapeutic interventions for breathing and sleep anomalies.

The Emerging Role of Drug-Induced Sleep Endoscopy in the Management of Obstructive Sleep Apnea

Obstructive sleep apnea is a prevalent sleep disorder characterized by partial or complete obstruction of the upper airway. Continuous positive airway pressure is the first-line therapy for most patients, but adherence is often poor. Alternative treatment options such as mandibular advancement devices, positional therapy, and surgical interventions including upper airway stimulation target different levels and patterns of obstruction with varying degrees of success. Drug-induced sleep endoscopy enables the visualization of upper airway obstruction under conditions mimicking sleep. In the era of precision medicine, this additional information may facilitate better decision-making when prescribing alternative treatment modalities, with the hope of achieving better adherence and/or success rates. This review discusses the current knowledge and evidence on the role of drug-induced sleep endoscopy in the non-positive airway pressure management of obstructive sleep apnea.

The Jaw Epidemic: Recognition, Origins, Cures, and Prevention

Contemporary humans are living very different lives from those of their ancestors, and some of the changes have had serious consequences for health. Multiple chronic "diseases of civilization," such as cardiovascular problems, cancers, ADHD, and dementias are prevalent, increasing morbidity rates. Stress, including the disruption of traditional sleep patterns by modern lifestyles, plays a prominent role in the etiology of these diseases, including obstructive sleep apnea. Surprisingly, jaw shrinkage since the agricultural revolution, leading to an epidemic of crooked teeth, a lack of adequate space for the last molars (wisdom teeth), and constricted airways, is a major cause of sleep-related stress. Despite claims that the cause of this jaw epidemic is somehow genetic, the speed with which human jaws have changed, especially in the last few centuries, is much too fast to be evolutionary. Correlation in time and space strongly suggests the symptoms are phenotypic responses to a vast natural experiment-rapid and dramatic modifications of human physical and cultural environments. The agricultural and industrial revolutions have produced smaller jaws and less-toned muscles of the face and oropharynx, which contribute to the serious health problems mentioned above. The mechanism of change, research and clinical trials suggest, lies in orofacial posture, the way people now hold their jaws when not voluntarily moving them in speaking or eating and especially when sleeping. The critical resting oral posture has been disrupted in societies no longer hunting and gathering. Virtually all aspects of how modern people function and rest are radically different from those of our ancestors. We also briefly discuss treatment of jaw symptoms and possible clinical cures for individuals, as well as changes in society that might lead to better care and, ultimately, prevention.

Maxillomandibular Advancement and Upper Airway Stimulation: Extrapharyngeal Surgery for Obstructive Sleep Apnea

There are many ways to categorize surgery for obstructive sleep apnea (OSA), one of which is to distinguish between intrapharyngeal and extrapharyngeal procedures. While the general otolaryngologist treating OSA is familiar with intrapharyngeal procedures, such as uvulopalatopharyngoplasty and tongue base reduction, extrapharyngeal sleep operations such as maxillomandibular advancement (MMA) and upper airway stimulation (UAS) have evolved rapidly in the recent decade and deserve a dedicated review. MMA and UAS have both shown predictable high success rates with low morbidity. Each approach has unique strengths and limitations, and for the most complex of OSA patients, the two in combination complement each other. Extrapharyngeal airway operations are critical for achieving favorable outcomes for sleep surgeons.

Surgical Algorithm for Obstructive Sleep Apnea: An Update

Sleep surgery is part of a continuum of care for obstructive sleep apnea (OSA) that involves medical, pharmacologic, and behavioral therapy. Upper airway surgery for OSA can significantly improve stability by way of modulating the critical negative closing pressure. This is the same mechanism of action as positive airway pressure or oral appliance therapy. The updated surgical algorithm in this review adds precision in three areas: patient selection, identification of previously unaddressed anatomic phenotypes with associated treatment modality, and improved techniques of previously established procedures. While the original Riley and Powell phase 1 and 2 approach to sleep surgery has focused on individual surgical success rate, this algorithm strives for an overall treatment success with multi-modal and patient-centric treatments.

Patterns of Obstruction on DISE in Adults With Obstructive Sleep Apnea Change With BMI

OBJECTIVES

We describe drug-induced sleep endoscopy (DISE) obstruction patterns in adults with obstructive sleep apnea (OSA) based on body mass index (BMI). We also evaluate subgroups of patients with clinically significant obstruction patterns at the velopharynx and oropharynx.

STUDY DESIGN

Retrospective chart review.

METHODS

Single-institution, retrospective chart review of adults with OSA who underwent DISE with dexmedetomidine sedation from 2016 to 2018. Endoscopic findings were graded using VOTE (Velum, Oropharynx, Tongue base, Epiglottis) classification. Oropharyngeal obstruction was additionally graded with the modifier T when due to palatine tonsil tissue. Findings in patients who had BMI < 25, 25 ≤ BMI < 30, and BMI ≥ 30 were compared.

RESULTS

One hundred and eleven patients (1 underweight, 23 normal weight, 56 overweight, and 31 obese) were reviewed. Patients with lower BMI were more likely to have more severe obstruction at the level of the tongue base (χ2 = 11.52, P = .021) and epiglottis (χ ² = 10.56, P = .032). Conversely, patients with higher BMI were more likely to have complete concentric (grade 2C) velum obstruction (χ ² = 16.04, P < .001) and more severe oropharyngeal obstruction (χ ² = 9.65, P = .046). Patients with grade 2 oropharyngeal obstruction without tonsil obstruction had more severe concurrent velum obstruction compared to subjects with grade 2 T oropharyngeal obstruction (P = .009).

CONCLUSION

In adults with OSA, BMI categories have significantly distinct obstruction patterns at all airway levels on DISE, and there appear to be distinct subgroups associated with certain velum and oropharynx collapse patterns. These findings may have important implications for positive airway pressure-alternative treatment.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:224-229, 2021.

Skeletal Surgery for Obstructive Sleep Apnea

This article focuses on the role of skeletal surgery within the modified Stanford protocol with particular attention focused on the evolved role of MMA. First, surgery in patients presenting with congenital dentofacial deformity or characteristic drug-induced sleep endoscopy findings, then the growing role of maxillary expansion in a newly identified patient phenotype, and finally genioglossus advancement, are discussed. Less commonly used and validated techniques, such as isolated mandibular advancement and maxillomandibular expansion are not discussed in this article.

Palatopharyngoplasty and Palatal Anatomy and Phenotypes for Treatment of Sleep Apnea in the Twenty-first Century

Successful palatopharyngoplasty is critical for successful sleep apnea surgery. Traditional uvulopalatopharyngoplasty was primarily excisional, whereas newer techniques, such as expansion sphincterpharyngoplasty, are more reconstructive. Studies of flow dynamics even demonstrate that the effectiveness of maxillofacial surgery is significantly mediated through stiffening and enlargement of the lateral retropalatal and pharyngeal airway. The current modified technique of uvulopalatopharyngoplasty/expansion sphincteroplasty aims to maximize relocation and tension on the palatopharyngeus muscle, opening the retropalatal airway and the palatal genu, and minimizing tension on the final mucosal closure.

Application of Computational Fluid Dynamics Analysis after Bimaxillary Orthognathic Surgery

Bimaxillary orthognathic surgery is widely used to treat skeletal class III malocclusion. Changes in jaw position affect the shape of surrounding soft tissues. We used computational fluid dynamics (CFD) simulation to observe changes in airways observed in a patient who underwent bimaxillary orthognathic surgery. For CFD simulation, we performed cone beam computed tomography (CBCT) preoperatively (T0), 3 days postoperatively (T1), and 7 months postoperatively (T2). The values of velocity, pressure drop (ΔP), and wall shear stress all increased 7 months after surgery (Vmax 7.038 m/s to 12.054 m/s, ΔP −7.723 Pa to −53.739 Pa, WSSmax 4.214 Pa to 14.323 Pa). Locations where the velocity and pressure gradients are large included the velopharynx, oropharynx, and epiglottis, with narrow cross-sectional areas. Wall shear stress was also observed at these locations. The velopharynx, oropharynx, and epiglottis are structures most vulnerable to morphological changes, that is, they can easily become obstructed.

Drug-Induced Sleep Endoscopy: Evaluation of a Selection Tool for Treatment Modalities for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a very common disorder with important day and nighttime symptoms and long-term effects on health. Different treatment modalities such as positive airway pressure (PAP), oral appliance therapy using custom-made, titratable mandibular advancement devices (MAD), different types of surgery and positional therapy have been introduced over the years, with patient preference and adherence to therapy being key elements in improving treatment outcomes. Several patient selection tools to improve treatment outcomes have been introduced and evaluated over the years. Drug-induced sleep endoscopy (DISE) is a procedure that provides real-time upper airway evaluation of the sites of flutter and upper airway collapse. This review focuses on the indications and contraindications for DISE, methods of sedation and evaluation, add-on maneuvers, and the results on patient selection and treatment outcomes. A PICO approach was used to clarify the aims of this review. DISE has the advantage of being easily accessible in most ENT practices and being 3-dimensional, dynamic, site specific, safe and it is valuable in selecting patients for upper airway surgery and oral appliance therapy. There is a strong interest for further standardization and exploration of the predictive value of this evolving technique.

Optimizing mandibular sagittal split of large maxillomandibular advancements for obstructive sleep apnea: patient and surgical factors

OBJECTIVES

Maxillomandibular advancement (MMA) confers consistent and high rates of surgical success for obstructive sleep apnea (OSA). In the era of value-based medicine, identifying factors that affect the stability of rigid fixation and allow rapid return to function are important targets for improvement. The aim of this study was to identify patient and surgical factors associated with mandibular sagittal split outcomes associated with optimal postoperatively skeletal stability.

STUDY DESIGN

Retrospective cohort study.

MATERIALS AND METHODS

Forty-six subjects (43 males and 3 females) with postoperative CT scans including three-dimensional reconstruction from which mandibular split patterns could be analyzed were enrolled. Patient factors (age and polysomnographic measures) and surgical factors (extent of osteotomy prior to controlled fracture) were assessed. Outcome measures include (1) bone thickness for rigid fixation and (2) area of passive bony overlap after advancement.

RESULTS

Age and severity of disease did not contribute significantly to optimal mandibular split patterns. For optimal area for passive bony overlap and thickness of buccal and lingual plates for rigid fixation, the most important factors are related to surgical technique.

CONCLUSIONS

Anterior osteotomy just to the midline of inferior border and horizontal osteotomy to the mandibular foramen are associated with split patterns that result in optimal rigid fixation and passive bony overlap for OSA patients undergoing MMA.

CLINICAL RELEVANCE

Optimal surgical technique has the most significant influence in allowing rapid return to function after MMA in patients with OSA.

High-Flow Nasal Cannula and Mandibular Advancement Bite Block Decrease Hypoxic Events during Sedative Esophagogastroduodenoscopy: A Randomized Clinical Trial

During sedated endoscopic examinations, upper airway obstruction occurs. Nasal breathing often shifts to oral breathing during open mouth esophagogastroduodenoscopy (EGD). High-flow nasal cannula (HFNC) which delivers humidified 100% oxygen at 30 L min⁻¹ may prevent hypoxemia. A mandibular advancement (MA) bite block with oxygen inlet directed to both mouth and nose may prevent airway obstruction during sedated EGD. The purpose of this study was to evaluate the efficacy of these airway devices versus standard management. One hundred and eighty-nine patients were assessed for eligibility. One hundred and fifty-three were enrolled. This study randomly assigned eligible patients to three arms: the standard bite block and standard nasal cannula, HFNC, and MA bite block groups. EGD was performed after anaesthetic induction. The primary endpoint was the oxygen desaturation area under curve at 90% (AUC_Desat). The secondary endpoints were percentage of patients with hypoxic, upper airway obstruction, and apnoeic and rescue events. One hundred and fifty-three patients were enrolled. AUCdesat was significantly lower for HFNC and MA bite blocks versus the standard management (p= 0.019). The HFNC reduced hypoxic events by 18% despite similar airway obstruction and apnoeic events as standard group. The MA bite block reduced hypoxic events by 12% and airway obstructions by 32%. The HFNC and MA groups both showed a 16% and 14% reduction in the number of patients who received rescue intervention, respectively, compared to the standard group. The HFNC and MA bite block may both reduce degree and duration of hypoxemia. HFNC may decrease hypoxemic events while maintaining nasal patency is crucial during sedative EGD. The MA bite block may prevent airway obstruction and decrease the need for rescue intervention.

The Role of the Revised Stanford Protocol in Today's Precision Medicine

Whereas the original Stanford protocol relied on a tiered approach to care to avoid unnecessary surgery, it did not address the issue of surgical relapse, a common concern among sleep medicine specialists. With 3 decades of experience since the original 2-tiered Powell-Riley protocol was introduced and the role of evolving skeletal techniques and upper airway stimulation, we are pleased to present our current protocol. This update includes emphasis on the facial skeletal development with impact on function including nasal breathing, and the incorporation of upper airway stimulation. The increased versatility of palatopharyngoplasty as an adjunctive procedure is also discussed.

Maxillomandibular Advancement: Contemporary Approach at Stanford

Maxillomandibular advancement (MMA) for the treatment of obstructive sleep apnea (OSA) has remained a reliable and highly effective surgical intervention since its introduction in 1989. Modifications have been made to maximize skeletal movement and upper airway stability without compromising facial balance. Contemporary indications of recommending MMA prior to other soft tissue surgery are described. MMA poses unique challenges to surgeons. There are patient-related factors, including OSA, a chronic inflammatory condition with associated cardiovascular and metabolic comorbidity. Perioperative management is more complex than routine orthognathic patients. Key details are shared from a 3-decade experience at Stanford.

Long-term Results for Maxillomandibular Advancement to Treat Obstructive Sleep Apnea: A Meta-analysis

Objective

To examine outcomes in the intermediate term (1 to <4 years), long term (4 to <8 years), and very long term (≥8 years) for maxillomandibular advancement (MMA) as treatment for obstructive sleep apnea (OSA).

Data Sources

The Cochrane Library, Google Scholar, Embase, Cumulative Index to Nursing and Allied Health, and PubMed/MEDLINE.

Review Methods

Three authors systematically reviewed the international literature through July 26, 2018.

Results

A total of 445 studies were screened, and 6 met criteria (120 patients). Thirty-one patients showed a reduction in apnea-hypopnea index (AHI) from a mean 48.3 events/h (95% CI, 42.1-54.5) pre-MMA to 8.4 (95% CI 5.6, 11.2) in the intermediate term. Fifty-four patients showed a reduction in AHI from a mean 65.8 events/h (95% CI, 58.8-72.8) pre-MMA to 7.7 (95% CI 5.9, 9.5) in the long term. Thirty-five showed a reduction in AHI from a mean 53.2 events/h (95% CI 45, 61.4) pre-MMA to 23.1 (95% CI 16.3, 29.9) in the very long term. Improvement in sleepiness was maintained at all follow-up periods. Lowest oxygen saturation improvement was maintained in the long term.

Conclusion

The current international literature shows that patients with OSA who were treated with MMA maintained improvements in AHI, sleepiness, and lowest oxygen saturation in the long term; however, the mean AHI increased to moderate OSA in the very long term. Definitive generalizations cannot be made, and additional research providing individual patient data for the intermediate term, long term, and very long term is needed.

The Effects of Noncontinuous Positive Airway Pressure Therapies on the Aerodynamic Characteristics of the Upper Airway of Obstructive Sleep Apnea Patients: A Systematic Review

PURPOSE

The effects of noncontinuous positive airway pressure (non-CPAP) therapies on the airflow in the upper airway in obstructive sleep apnea (OSA) patients are not completely clear yet. Therefore, the primary aim of this systematic review was to determine the effects of various non-CPAP therapies on the aerodynamic characteristics of the upper airway in OSA patients.

MATERIALS AND METHODS

A PICO (population or patient, intervention, comparison, outcome) search strategy, focusing on the effects of various non-CPAP therapies on the aerodynamic characteristics of the upper airway (ie, velocity, wall shear stress, wall static pressure, airway resistance, pressure drop, and pressure effort) of OSA patients, was conducted in the following databases: MEDLINE (PubMed), Embase (Excerpta Medica), and Web of Science. In this systematic review, the inclusion criteria were 1) adults diagnosed with OSA by polysomnography, 2) treatment outcome assessed by a second polysomnography, and 3) computational fluid dynamics (CFD) applied.

RESULTS

Of 51 unique studies retrieved, 9 fulfilled the criteria for this systematic review. Seven studies were on maxillomandibular advancement (MMA) surgery, and 2 were on mandibular advancement device (MAD) therapy. The aerodynamic characteristics of the upper airway improved in OSA patients who underwent MMA surgery. However, the studies on MMA surgery included only responders to MMA surgery. In the responders to MAD therapy, the velocity, wall static pressure, and airway resistance of the upper airway decreased. In nonresponders to MAD therapy, the wall static pressure and airway resistance of the upper airway increased.

CONCLUSIONS

This systematic review suggests that MMA surgery and MAD therapy may improve several aerodynamic characteristics of the upper airway in OSA patients by CFD analysis. However, because of limitations of the selected studies, there is not enough evidence yet to support CFD analysis as a routine tool to predict the treatment outcome in OSA patients.

Analyses of aerodynamic characteristics of the oropharynx applying CBCT: obstructive sleep apnea patients versus control subjects

OBJECTIVES

To determine the most relevant aerodynamic characteristic of the oropharynx related to the collapse of the upper airway in obstructive sleep apnea (OSA) patients; and to determine the correlation between the most relevant aerodynamic characteristic(s) of the oropharynx and anatomical characteristics of the oropharynx in OSA patients.

METHODS

31 mild to moderate OSA patients (mean ± SD age = 43.5 ± 9.7 years) and 13 control subjects (mean ± SD age = 48.5 ± 16.2 years) were included in this prospective study. The diagnosis of OSA patients was based on an overnight polysomnographic recording. To exclude the presence of OSA in the control subjects, they were asked to fill out a validated questionnaire to determine the risk of OSA. NewTom5G cone beam CT (CBCT) scans were obtained from both OSA patients and control subjects. Computational models of the oropharynx were reconstructed based on CBCT images. The aerodynamic characteristics of the oropharynx were calculated based on these computational models. Pearson correlation analysis was used to analyse the correlation between the most relevant aerodynamic characteristic(s) and anatomical characteristics of the oropharynx in OSA patients.

RESULTS

Compared with controls, the airway resistance during expiration (R_ex) of the OSA patients was significantly higher (p = 0.04). There was a significant negative correlation between R_ex and the minimum cross-sectional area (CSA_min) of the oropharynx (r = -0.41, p = 0.02), and between R_ex and the volume of the oropharynx (r = -0.48, p = 0.01) in OSA patients. After excluding an outlier, there is only significant correlation between R_ex and the CSA_min of the oropharynx (r = -0.45, p = 0.01).

CONCLUSIONS

Within the limitations of this study, we concluded that the most relevant aerodynamic characteristic of the oropharynx in the collapse of the upper airway in OSA patients is R_ex. Therefore, the repetitive collapse of the upper airway in OSA patients may be explained by a high R_ex, which is related to the CSA_min of the oropharynx.

Systematic Review of Drug-Induced Sleep Endoscopy Scoring Systems

Objective To systematically review the scoring systems used to report findings during drug-induced sleep endoscopy (DISE) for adults and children with obstructive sleep apnea. Data Sources PubMed, CINAHL, EBM Reviews, Embase, and Scopus databases. Review Methods This is a systematic review of all indexed years of publications referring to scoring of DISE for children and adults with obstructive sleep apnea. The type of DISE scoring system utilized was the primary outcome. PRISMA guidelines were followed to carry out this review; articles were independently reviewed by 2 investigators. All pediatric and adult studies that utilized ≥1 DISE grading systems were included. Results Of 492 identified abstracts, 44 articles (combined population, N = 5784) were ultimately included; 6 reported on children, 35 on adults, and 1 on children and adults. Twenty-one reporting methods were used in these studies, with the most common being the VOTE system (velum, oropharynx, tongue base, and epiglottis; 38.6%) and the Pringle and Croft classification (15.9%). The sites of obstruction most commonly included in a scoring system were the tongue base (62%), lateral pharynx/oropharynx (57%), palate (57%), epiglottis/supraglottis (38%), and hypopharynx (38%). Less commonly included sites were the larynx (29%), velum (23%), nose (23%), tongue (14%), adenoids (10%), and nasopharynx (10%). Conclusion There is no consensus regarding which scoring system should be utilized to report findings during DISE. The VOTE system and the Pringle and Croft classification were the most frequent scoring systems reported for patients undergoing DISE. Standardization of the reporting of DISE findings would improve comparability among studies.

Investigation of the effects of miniscrew-assisted rapid palatal expansion on airflow in the upper airway of an adult patient with obstructive sleep apnea syndrome using computational fluid-structure interaction analysis

OBJECTIVE

The objective of this study was to investigate the effects of miniscrew-assisted rapid palatal expansion (MARPE) on changes in airflow in the upper airway (UA) of an adult patient with obstructive sleep apnea syndrome (OSAS) using computational fluid-structure interaction analysis.

METHODS

Three-dimensional UA models fabricated from cone beam computed tomography images obtained before (T0) and after (T1) MARPE in an adult patient with OSAS were used for computational fluid dynamics with fluid-structure interaction analysis. Seven and nine cross-sectional planes (interplane distance of 10 mm) in the nasal cavity (NC) and pharynx, respectively, were set along UA. Changes in the cross-sectional area and changes in airflow velocity and pressure, node displacement, and total resistance at maximum inspiration (MI), rest, and maximum expiration (ME) were investigated at each plane after MARPE.

RESULTS

The cross-sectional areas at most planes in NC and the upper half of the pharynx were significantly increased at T1. Moreover, airflow velocity decreased in the anterior NC at MI and ME and in the nasopharynx and oropharynx at MI. The decrease in velocity was greater in NC than in the pharynx. The airflow pressure in the anterior NC and entire pharynx exhibited a decrease at T1. The amount of node displacement in NC and the pharynx was insignificant at both T0 and T1. Absolute values for the total resistance at MI, rest, and ME were lower at T1 than at T0.

CONCLUSIONS

MARPE improves airflow and decreases resistance in UA; therefore, it may be an effective treatment modality for adult patients with moderate OSAS.

Insights since FDA Approval of Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

Purpose

The literature on hypoglossal nerve stimulation (HNS) for the treatment of moderate-to-severe obstructive sleep apnea (OSA) was reviewed from 2014, the time of FDA approval for the Inspire Systems device, to 2017 for themes that might be useful conceptually and practically in the consideration of this new non-anatomic surgical therapy.

Recent Findings

there are now further follow-up articles since the 12-month results for Apnea Reduction (STAR) trial of the Inspire device, and post-approval publications which report similar and/0r improved AHI outcomes. Other emerging themes include drug-induced sedation endoscopy (DISE) as a tool in assessment of eligibility and a more detailed understanding of mechanisms for an HNS effects.

Summary

The post-STAR literature provides guidelines for an integrated coordination of medicine and surgery to appropriately screen and manage patients.

Restoration of Sleep Architecture after Maxillomandibular Advancement: Success Beyond the Apnea-Hypopnea Index

While effects of maxillomandibular advancement (MMA) on respiratory parameters for patients with obstructive sleep apnea (OSA) are well described, effects on sleep architecture before and after MMA are not. A retrospective cohort analysis on sleep architecture was examined in 10 OSA patients who underwent MMA surgery between July 2013 and November 2014, and had prespecified complete polysomnography (PSG) datasets. Sleep stages were examined relative to a Western European population-based control group. All of the respiratory parameters improved significantly post MMA. Rapid eye movement (REM) latency decreased from 178.0±142.8 to 96.6±64.5min (P=0.035). %NREM (non-rapid eye movement)1 (P=0.045) and %WASO (wakefulness after sleep onset) (P=0.006) decreased, while %REM increased (P=0.002) after MMA. WASO decreased from 64.2±57min to 22.4±15.4min (P=0.017). Preoperatively, OSA subjects showed significantly lower sleep efficiency (P=0.016), sleep onset latency (P=0.015), and % REM (P<0.001) than the normative population dataset, while post MMA there was a significant decrease in %NREM1 sleep (P<0.001) and in %WASO (P<0.001). MMA results in a marked decrease in WASO and increase in REM, and to a lesser extent NREM sleep. Patients after MMA show values similar to population controls except for a lower WASO.