Advanced Diagnostic Techniques in Obstructive Sleep Apnea

Optimal surgical and medical management of obstructive sleep apnea requires clinically reliable identification of patterns and sites of upper airway obstruction. A wide variety of modalities have been used to evaluate upper airway obstruction. Drug-induced sleep endoscopy (DISE) and cine MRI are increasingly used to identify upper airway obstruction sites, to characterize airway obstruction patterns, to determine optimum medical and surgical treatment, and to plan individualized surgical management. Here, we provide an overview of the applications of DISE and cine MRI in assessing upper airway obstruction in children and adults with obstructive sleep apnea.

The effect of drug-induced sleep endoscopy on surgical outcomes for obstructive sleep apnea: a systematic review

PURPOSE

Drug-induced sleep endoscopy (DISE) is the most widespread diagnostic tool for upper-airway endoscopic evaluation of snoring and obstructive sleep apnea (OSA). However, a consensus on the effectiveness of DISE on surgical outcomes is still lacking. This study aimed to quantify the effect of DISE on surgical outcomes and to compare DISE with awake examination using the Müller Maneuver (MM).

METHODS

This systematic review was performed according to the PRISMA guidelines. Published studies from the last 30 years were retrieved from the Cochrane Library, MEDLINE, SCOPUS, and PubMed databases. Studies comparing DISE with awake examination, or MM were included. Surgical success rate was defined according to Sher's criteria, achieving a postoperative apnoea-hypopnea index (AHI) value < 20 events per hour and a 50% improvement from preoperative AHI. Outcomes are presented in terms of surgical success, pre- and postoperative AHI, Epworth sleepiness score (ESS), oxygen desaturation index (ODI) and lowest oxygen saturation (LOS).

RESULTS

This review included 8 studies comprising 880 patients. DISE group showed a higher LOS increase, ODI decrease, ESS decrease than non-DISE group (6.83 ± 3.7 versus 3.68 ± 2.9, p<0.001; 19.6 ± 11.2 versus 12.6 ± 10.4, p<0.001; 6.72 ± 4.1 versus 3.69 ± 3.1, p<0.001). Differences in surgical success rate were significant only between DISE and MM (64.04% versus 52.48%, p = 0.016). AHI decrease resulted higher in non-DISE than in DISE group (39.92 ± 24.7 versus 30.53 ± 21.7, p<0.001).

CONCLUSION

Results of this systematic review suggest that the evidence is mixed regarding a positive effect of DISE on surgical outcomes.

The Prevalence of Sentinel Central Events (SCent) During Drug-Induced Sleep Endoscopy

OBJECTIVE

With the recent addition of airflow and respiratory effort channels, our group has observed central and mixed apnea events during drug-induced sleep endoscopy (DISE). We measured the frequency and timing of sentinel central and/or mixed events (SCents), as well as assessed for differences in velum, oropharynx, tongue, and epiglottis (VOTE) classification compared to obstructive events.

STUDY DESIGN

Prospective single-cohort study.

SETTING

Tertiary Care Academic Medical Center.

METHODS

Patients underwent DISE between June 2020 and November 2022. Nasal airflow, thoracoabdominal effort belt signals, and videoendoscopy were simultaneously captured. Demographics, sleep study, and DISE data were compared among patients with and without SCents using Student's T tests or χ2 tests.

RESULTS

On average, the cohort (n = 103) was middle-aged (53.5 ± 12.1 years), overweight (body mass index of 29.7 ± 5.3 kg/m2), and had severe obstructive sleep apnea (apnea-hypopnea index of 30.7 ± 18.7 events/h). Forty-seven patients (46%) were found to have at least 1 SCent. Among those with SCent, 45 (95.7%) transitioned to obstructive pathology after an average of 7.91 ± 2.74 minutes, with at least 95% of patients expected to do so within 12.57 minutes. Twenty-nine out of 47 patients (61.2% [95% confidence interval: 46.4.9%, 75.5%]) with SCent had meaningful differences between central/mixed and obstructive VOTE scores.

CONCLUSION

Central events were present in almost half of our cohort. At least 95% of patients were expected to transition to obstructive events within 12 to 13 minutes of propofol initiation. In addition, over half of patients demonstrate significantly different VOTE scores between central and obstructive events. These factors should raise awareness of central events and scoring passive apneas during DISE and consider delaying VOTE scoring.

Advanced Diagnostic Techniques in Obstructive Sleep Apnea

Optimal surgical and medical management of obstructive sleep apnea (OSA) requires clinically reliable identification of patterns and sites of upper airway obstruction. A wide variety of modalities has been used to evaluate upper airway obstruction. Drug-induced sleep endoscopy (DISE) and cine MRI are increasingly used to identify upper airway obstruction sites, to characterize airway obstruction patterns, to determine optimum medical and surgical treatment, and to plan individualized surgical management. Here, the authors provide an overview of the applications of DISE and cine MRI in assessing upper airway obstruction in children and adults with OSA.

Predictors of Success of Pharyngeal Surgery in the Treatment of Obstructive Sleep Apnea: A Narrative Review

(1) Background: This narrative review aims to explore the predictors of success for pharyngeal surgery in the treatment of obstructive sleep apnea (OSA). An extensive literature search was conducted, identifying relevant studies published up to June 2023, utilizing various databases and key search terms related to OSA, surgical interventions, and predictors of success. The review encompasses both retrospective and prospective studies, case series, and cohort studies to provide a broad understanding of the topic; (2) Methods: Review of English scientific literature on phenotypes of OSA related to predictors of success of pharyngeal surgery; (3) Results: Of 75 articles, 21 were included, in these the following were determined to be factors for surgical success: body mass index (BMI) (8 articles), apnea/hypopnea index (AHI) (8 articles), cephalometry (8 articles), palatine tonsil size (7 articles), Modified Mallampati score (2 articles), genioglossus electromyography (2 articles), Friedman score or upper airway anatomy (3 articles), nasopharyngolaryngoscopy (2 articles), drug-induced sleep endoscopy (DISE) (1 article), oral cavity anatomy (1 article) and oxygen desaturation index (ODI) (1 article); (4) Conclusions: The lack of standardized protocols for the indication of pharyngeal surgery is a reality, however identifying known predictors of surgical success may facilitate homogenizing indications.

Multilevel Airway Obstruction Phenotypes in Adult OSA

Objective

To describe multilevel phenotypes of airway obstruction identified on drug-induced sleep endoscopy (DISE) in adults.

Study Design

Retrospective chart review.

Setting

Tertiary care center.

Methods

Video recordings of DISE on adult patients were retrospectively scored. A cross-correlation matrix was created to detect significant correlations between DISE findings at anatomical subsites. Three multilevel phenotypes resulted from the matrix: complete collapse at the tongue base with complete collapse at the epiglottis (T2-E2), complete circumferential obstruction at the velum with complete lateral pharyngeal wall collapse at the oropharynx (V2C-O2LPW), and incomplete collapse at the velum with complete collapse due to tonsillar hypertrophy (V0/1-O2T). The mean difference (MD) and 95% confidence interval (CI) were calculated for demographic and polysomnogram metrics of each phenotype compared to all other subjects.

Results

Phenotype 1 (T2-E2) (n = 88) had older ages (MD 5.784 years, CI [1.992, 9.576]), lower body mass index (BMI) (MD -1.666 kg/m², CI [02.570, -0.762]), and smaller neck circumferences (MD -0.448 in., CI [-9.14, -0.009]) than the other phenotypes. Phenotype 2 (V2C-O2LPW) (n = 25) had higher BMIs (MD 2.813 kg/m², CI [1.362, 4.263]), higher neck circumference (MD 0.714 in., CI [0.004, 1.424]), and higher apnea-hypopnea index (MD 8.252, CI [0.463, 16.041]). Phenotype 3 (V0/1-O2T) (n = 20) had younger ages (MD -17.697, CI [-25.215, -11.179]).

Conclusion

Three distinct multilevel phenotypes of obstruction were identified on DISE, suggesting different anatomic subsites collapse in a nonrandom pattern. The phenotypes appear to represent distinct patient groups and their identification may have implications in terms of pathophysiology and treatment modalities.

Is drug-induced sleep endoscopy associated with better outcomes after soft tissue surgery for sleep apnea? A systematic review and meta-analysis

OBJECTIVES

The aim was to estimate the effect of drug-induced sleep endoscopy (DISE) on surgical outcomes after soft tissue surgery for obstructive sleep apnea (OSA).

DESIGN AND SETTING

Systematic review and meta-analysis.

PARTICIPANTS

Adult patients with OSA and candidates for soft tissue surgery, with and without preoperative DISE, were included.

MAIN OUTCOMES MEASURES

A systematic literature search of Medline, Web of Science, and Cochrane databases was performed from inception to December 31, 2021. Studies directly comparing patients with and without preoperative DISE were included. Success rate, change in apnea-hypopnea index (AHI), change in minimum SpO₂ and change in Epworth Sleepiness Scale (ESS) score were extracted. Random-effect models were used to pool estimates.

RESULTS

Seven out of 619 articles were included, representing 791 patients (389 in the DISE group and 402 in the no DISE group). DISE was neither associated with a higher success rate (pooled OR 1.34, 95% CI 0.69-2.59, p = 0.39) after soft tissue surgery for OSA, nor a significant change in AHI (-4.69 events/hour, 95% CI -11.10 to 1.72, p = 0.15), minimal SpO₂ (mean increase of 2.02%, 95% CI -0.26 to 4.29, p = 0.08) and ESS (mean difference of 1.29, 95% CI -0.48 to 3.05, p = 0.15) when compared to patients without preoperative DISE.

CONCLUSIONS

Soft tissue surgery does not give better results after DISE compared to when DISE is not performed. However, given the overall low level of evidence of included studies, future well-conducted studies should confirm or overturn these results and clarify the added value of DISE.

Effects of Soft Tissue Sleep Surgery on Morbidly Obese Patients

INTRODUCTION

Morbidly obese patients with obstructive sleep apnea (OSA) are often intolerant of continuous positive airway pressure (CPAP). The effects of sleep surgery in this population is not well documented, and sleep surgery is generally avoided due to the expectation of poor outcomes, leaving these patients untreated.

METHODS

This retrospective study included 42 patients with a body mass index (BMI) ≥40.0 and OSA with a preoperative apnea hypopnea index (AHI) ≥5. Preoperative BMI ranged from 40.0 to 69.0 kg/m². Preoperative AHI ranged from 7.2 to 130.0. Of 42 patients, 12 (28.6%) underwent concurrent pharyngeal and retrolingual surgery. Subgroup analysis of change in AHI was measured with respect to preoperative OSA severity, change in preoperative BMI, and BMI severity. Univariate linear and logistic regression was performed assessing change in AHI and surgical success with respect to age, sex, preoperative AHI, preoperative BMI, change in BMI, total procedures, palatal procedure, retrolingual procedure, nasal procedure, and multilevel procedures.

RESULTS

The mean AHI improved from 45.9 ± 31.8 to 31.9 ± 31.6 (P = .007). Epworth sleepiness score (ESS) improved from 13.2 ± 5.5 to 9.6 ± 5.4 (P = .00006). Lowest oxygen saturation (LSAT) improved from 74.4 ± 10.7 to 79.9 ± 10.4 (P = .002). About 33.3% of patients had surgical success (AHI < 20 with at least 50% reduction in AHI). Preoperative AHI was the most significant factor for change in AHI in univariate and multivariate models (P = .015).

CONCLUSION

Sleep surgery is effective in reducing OSA burden in most morbidly obese patients and can result in surgical cure for a third of patients.

Palatal Coupling Maneuvers Do Not Predict Hypoglossal Nerve Stimulator Treatment Efficacy

OBJECTIVE(S)

Maneuvers during drug-induced sleep endoscopy (DISE), for patients with obstructive sleep apnea (OSA), have been used as predictors for success with oral appliances. Hypoglossal nerve stimulation (HGNS) promotes opening at the velum through palatoglossus coupling. In this study, we evaluate maneuvers during DISE as predictors for HGNS treatment efficacy.

METHODS

We evaluated patients undergoing HGNS between November, 2014 and February, 2021. We assessed maneuvers including jaw thrust and chin lift during preoperative DISE. The impact of tongue base and palatal opening during these maneuvers were rated from 1 to 4 (1: no improvement, 2: mild improvement, 3: moderate improvement, 4: significant improvement). Patients were grouped by a score of 1-2 (weak response) or 3-4 (strong response). Apnea hypopnea index (AHI) change was calculated from the difference between preoperative and postoperative sleep study.

RESULTS

One hundred and seventy one patients were included. With jaw thrust, there was no significant difference in AHI change between patients with weak or strong response at the palate (n = 68 vs. 94, 9.5 vs. 13.6, p = 0.21) or tongue base (n = 24 vs. 138, 16.6 vs. 11.3, p = 0.24). On chin lift, there was no significant difference at the palate (n = 82 vs. 18, 13.9 vs. 11.4, p = 0.63) or tongue base (n = 92 vs. 72, 10.8 vs. 14.6, p = 0.24). On multiple linear regression analysis, lower body mass index, higher preoperative AHI, and higher preoperative oxygen nadir were associated with a larger AHI change.

CONCLUSION

Palatal coupling maneuvers during DISE are not predictive of AHI change with HGNS. Findings using these maneuvers should not preclude HGNS candidacy.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:431-436, 2023.

The clinical application progress and potential of drug-induced sleep endoscopy in obstructive sleep apnea

Background and Objective: Obstructive sleep apnoea (OSA) is characterized by nocturnal repetitive upper airway (UA) collapse. For sleep physicians, the recognition of UA collapse characteristics is critical for understanding OSA mechanisms and developing individualized treatment plans. Drug-induced sleep endoscopy (DISE) is an exam during simulated sleep that allows the dynamic assessment of the UA of individuals with OSA. The initial recognition of DISE was to locate the sites of UA obstruction and direct the surgical selection of OSA since it was introduced in the 1990s. After approximately 30 years of studies, based on advances in endoscopic operative techniques and innovative treatments of OSA, DISE had been performed to explore mechanisms and comprehensive treatments related to UA collapse. Methods: This article reviewed contemporary DISE advances, including indications and contraindications, technique of induced sleep, endoscopic operation, UA characteristics classification.Results and Conclusions: Precise selection based on the association between collapse patterns and treatment modalities, such as continuous positive airway pressure, oral appliance, positional therapy, robotic surgery and neurostimulator implanting, is the future research prospect based on DISE.Key messagesDISE provides sleep physicians with valuable information about the upper airway collapse characteristics and dynamic changes during sleep.The studies based on DISE findings improve the selectivity and efficiency of treatment modalities, including classical therapies such as continuous positive airway pressure, oral appliance, positional therapy, and innovative therapies such as neurostimulator implanting and robotic surgery, promote the advancement of OSA precision medicine.

Guidelines of the French Society of ENT (SFORL): Drug-induced sleep endoscopy in adult obstructive sleep apnea syndrome

OBJECTIVES

To determine the indications, anesthesiological and surgical procedure and interest of drug-induced sleep endoscopy in the treatment of adult obstructive sleep apnea syndrome.

DESIGN

A redactional committee of 17 experts was set up. Conflicts of interest were disclosed and followed up throughout the process of drawing up the guidelines. The work received no funding from any firm dealing in health products (drugs or devices). The GRADE (Grading of Recommendations Assessment, Development and Evaluation) method was applied to assess the quality of the data on which the guidelines were founded. It was stressed that strong recommendations should not be made on the basis of poor-quality or insufficient data.

METHODS

The committee studied 29 questions on 5 topics: indications and contraindications, anesthetic technique, surgical technique, interpretation and reporting of results, and management guided by results.

RESULTS

Expert review and application of the GRADE method led to 30 guidelines: 10 with high level of evidence (Grade 1+ or 1-), 19 with low level (GRADE 2+ or 2-) and 1 expert opinion.

CONCLUSION

Experts fully agreed on the strong guidelines formalizing the indications and modalities of drug-induced sleep endoscopy for adult obstructive sleep apnea syndrome.

Drug Induced Sleep Endoscopy Versus Awake Endoscopy in Retrolingual Obstruction Assessment in Obstructive Sleep Apnea Patients: A Comparative Study

ABSTRACT

The aim of this study is to evaluate the correlation of retrolingual obstruction determined by drug induced sleep endoscopy (DISE) and awake endoscopy evaluation of Muller maneuver (MM) and lingual tonsil hypertrophy (LTH) in patients with obstructive sleep apnea.A prospective cohort of 100 patients with obstructive sleep apnea who underwent DISE was assessed. The inclusion criteria were age between 18 and 70 years, and apnea-hypopnea index higher than 5. Friedman staging, LTH and MM were determined by awake endoscopy, as other physical findings. The authors evaluated the correlation of retrolingual obstruction determined by DISE using velum oropharynx tongue, epiglottis (VOTE) and nose, oropharynx, hypopharynx, larynx (NOHL) classification.When retrolingual MM was assessed, significant changes between awake and DISE were observed (P = 0.000). Conversely, Friedman stage had no significant changes to DISE retrolingual findings (P = 0.868). Analyzing LTH and DISE retrolingual findings according to NOHL and VOTE, if a cutoff value was established at 50%, DISE findings differ from awake: NOHL (P < 0.001) and VOTE (P = 0.004). Nevertheless, if a restrictive cutoff at 75% was attached, DISE findings were similar to awake: NOHL (P = 0.124) and VOTE (P = 0.123).This study demonstrates that awake endoscopy determining LTH and Friedman stage is a mild predictor of collapse at retrolingual level, showing significant correlation to DISE only when severe retrolingual collapse is present. Our findings suggest that in-office awake endoscopy may have certain predictive value to select surgical patients.

Effectiveness of drug-induced sleep endoscopy in improving outcomes of barbed pharyngoplasty for obstructive sleep apnea surgery: a prospective randomized trial

PURPOSE

To observe the effectiveness of preoperative drug-induced sleep endoscopy in improving surgical results of patients undergoing single-level barbed pharyngoplasty surgery for OSA, using a prospective randomized model.

METHODS

A single-center randomized controlled trial with two prospective arms was carried out to compare functional results in patients treated with barbed reposition pharyngoplasty (BRP) surgery without a preoperative drug-induced sleep endoscopy (DISE) evaluation vs patients treated with BRP surgery performed after DISE evaluation of sites/patterns of collapse.

RESULTS

We compared 50 patients who underwent BRP without a preoperative DISE evaluation (Group A) and 42 patients (Group B) treated with BRP surgery but preoperatively selected by means of a preoperative DISE. In this second group of patients, after DISE evaluation, 70% of patients were selected for single-level BRP surgery because they showed an isolated velopharyngeal collapse at the DISE evaluation, without obstruction at other upper airway levels evaluated. Both groups of patients showed a statistically significant difference between preoperative and postoperative values of AHI, ODI, and LOS (p<0.05 in all cases). Comparing Group A and Group B patients, the therapeutic success rate was found to be 60% in patients treated without preoperative DISE evaluation and 83% in patients treated with preoperative DISE (p = 0.02).

CONCLUSION

DISE appears to improve the surgical results of single-level velopharyngeal surgery due to the possibility of excluding patients with obstruction of the base of the tongue, the hypopharynx, and the epiglottis/larynx.

Systematic review and updated meta-analysis of multi-level surgery for patients with OSA

OBJECTIVES

To perform an updated systematic review for determining the surgical success rate of multilevel upper airway surgery for patients with obstructive sleep apnea/hypopnea syndrome (OSA).

METHODS

A systematic review was performed to identify English-language studies that evaluated the treatment of adult OSA patients with multilevel OSA surgery up to January, 2018. We used polysomnography as a metric of treatment success. Articles were only included if the surgery intervention involved at least two of the frequently involved anatomic sites: nose, oropharynx and hypopharynx. Eighty-seven studies fit the inclusion criteria and a meta-analysis was performed to determine the overall success.

RESULTS

The meta-analysis included 3931 subjects with a mean age of 46.1 years. The originally reported success rate in the included literature was 59.9%. A meta-analysis was performed to redefine the success rate to be consistent with the commonly agreed upon criteria - namely "a reduction in apnea/hypopnea index (AHI, /hr.) of 50% or more and an AHI of less than 20". The recalculated success rate was 60.2%. Standard meta-analytic techniques for combining p-values between studies after weighting for sample size found significant improvements in AHI, apnea index, % of rapid eye movement sleep, lowest saturation of oxygen (%), and Epworth Sleepiness Scale.

CONCLUSION

This study shows the significant improvement of treatment outcomes with multilevel surgery for OSA patients.

One-Stage Multilevel Surgery for Treatment of Obstructive Sleep Apnea Syndrome

We report the results of one-stage multilevel upper airway surgery for patients who could not tolerate continuous positive airway pressure (CPAP). Patients treated with multilevel surgery at a University Hospital in 2015–2019 were identified from a prospectively maintained database. The inclusion criteria were aged 18–70 years, body mass index (BMI) < 35 kg/m², apnea–hypopnea index (AHI) > 20, and lingual tonsil hypertrophy grade 3 or 4. Drug-induced sleep endoscopy was performed before surgery in all patients. Multilevel surgery was performed in one stage and included expansion sphincter pharyngoplasty (ESP), coblation tongue base reduction (CTBR), and partial epiglottectomy (PE) as required. The outcome measures were postoperative AHI, time percentage oxygen saturation < 90%, and Epworth Sleepiness Scale (ESS) score. A total of 24 patients were included: median age 49.1 years, average BMI 27.26 kg/m², and 90% men. Ten patients received ESP plus CTBR plus PE, eight received ESP plus CTBR, and six received ESP plus PE. The mean preoperative AHI was 33.01 at baseline and improved to 17.7 ± 13 after surgery (p < 0.05). The ESS score decreased from 11 ± 5.11 to 7.9 ± 4.94 (p < 0.05). The surgical success rate according to Sher’s criteria was 82.3%. The median follow-up was 23.3 months (range 12–36). These findings suggest that multilevel surgery is a safe and successful treatment of OSAHS.

Management of obstructive sleep apnea in children: a Canada-wide survey

BACKGROUND

Obstructive sleep apnea frequently persists in children following adenotonsillectomy, which is the first-line treatment recommended for obstructive sleep apnea with adenotonsillar hypertrophy. Drug-induced sleep endoscopy (DISE) is a diagnostic tool increasingly used to assess pediatric obstructive sleep apnea, but its use has not been standardized. The overarching goal of this study was to document the current practice of Canadian otolaryngologists managing this population.

METHODS

A nation-wide online cross-sectional survey of Canadian otolaryngologist members of the Canadian Society of Otolaryngology - Head and Neck Surgery and the Association d'otorhinolaryngologie et chirurgie cervico-faciale du Québec. The 58-question electronic survey was developed based on a validated survey redaction guide with the aim to assess management and treatment of pediatric obstructive sleep apnea, as well as indications and performance of DISE. Consensus on practice items was defined by a minimum of 75% similar answers.

RESULTS

One hundred and nine Canadian otolaryngologists completed the survey on management of pediatric obstructive sleep apnea, among which 12 of them completed the questions on DISE. Overall, there was a poor rate of agreement of 55% among the respondents for the 58 questions altogether. There was a consensus to assess pediatric obstructive sleep apnea clinically ± with videos (82.6%), to assess adenotonsillar hypertrophy clinically (93.6%) and with flexible scope in the office (80.7%), as well as for the airway sites examined endoscopically during DISE. However, there was no consensus regarding anesthetic protocol and scoring system. DISE was mostly performed in cases of persistent obstructive sleep apnea after adenotonsillectomy rather than before performing any surgical procedure. There was no difference in the management of obstructive sleep apnea between otolaryngologists who perform DISE and those who do not. The only difference between otolaryngologists who practice in community centers versus in tertiary care centers was the more frequently use of the Brodsky tonsil scale by the latter ones.

CONCLUSION

This Canadian-wide survey highlighted a lack of consensus in the management of pediatric obstructive sleep apnea and DISE. Certain aspects regarding DISE remain unclear, including establishment of its ideal timing in order to eventually avoid unnecessary tonsillectomies.

Comparison of surgical outcomes of sleep surgeries preoperatively evaluated with drug-induced sleep endoscopy and Müller's maneuver

Objective The purpose of this study was to compare surgical outcomes for obstructive sleep apnea (OSA) when the procedure was based on the results of drug-induced sleep endoscopy (DISE) vs. the awake Müller's maneuver (MM). Methods Forty-seven patients with OSA who underwent sleep surgery were included. Patients were divided into 2 groups according to their preoperative upper airway evaluation method. Twenty-five patients received only MM for surgical decision making (MM group), and 22 patients received both MM and DISE (DISE group) for surgical decision making. Results The surgical success rate of the DISE group was higher than that of the MM group (59% vs. 36%), but the difference was not significant (p = 0.118). The differences between pre- and postoperative apnea-hypopnea index (AHI) values in both the MM and DISE group were highly significantly different (p < 0.001). Fifteen patients in the DISE group (68.2%) received multi-level surgery, while in the MM group only 7 patients (28%) received multi-level surgery. Patients with more severe OSA (AHI > 22 or lowest O2 saturation < 81%) had better surgical outcomes when their surgical procedures were based on the findings of DISE, rather than those of MM. Conclusion The results indicate that DISE provides no benefits with respect to surgical outcomes for patients with mild to moderate OSA; however, for patients with more severe OSA surgical procedures based on DISE result in better outcomes.

A systematic approach to the evaluation and management of obstructive sleep apnea: The Jefferson Protocol

Obstructive sleep apnea (OSA) has become increasingly prevalent in the United States. While continuous positive airway pressure (CPAP) therapy remains the gold standard for treatment, surgical intervention can enhance compliance and improve outcomes for those intolerant of CPAP. Since the majority of OSA patients have multilevel obstruction, it is critical that otolaryngologists understand each patient's pattern and anatomic level of obstruction before solidifying a treatment plan. This publication serves as a comprehensive review of evaluation, characterization, and management of OSA. Further, the authors outline their departmental algorithm for identifying ideal surgical candidates and tailoring corresponding surgical interventions.

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.

[Conservative treatment of obstructive sleep apnea using non-PAP therapies]

In Germany about one third of adults aged between 30 and 69 years suffer from obstructive sleep apnea (OSA). Snoring, inspiratory flow limitations, hypopneas, and apneas occur, leading to disturbed sleep, reduced daytime performance, and increased cardiovascular morbidity and mortality. Positive airway pressure therapy (PAP therapy) can be successfully administered in every OSA severity. However, other conservative treatments have to be considered for some patients, particularly in PAP failure or intolerance. The individual treatment concept is based on poly(somno)graphic, morphological, and functional assessment, taking treatment acceptance, adherence, and compliance into account.

Drug-induced sleep endoscopy: techniques, interpretation and implications

PURPOSE OF REVIEW

The purpose of this article is to highlight recent advances in the burgeoning field of drug-induced sleep endoscopy (DISE).

RECENT FINDINGS

One of the first studies to investigate the correlation of DISE findings and natural sleep endoscopy found good agreement in clinically significant obstruction. Previous studies have shown good agreement of DISE findings with the use of different sedative agents implying that the choice of sedative may not be crucial. However, recent studies show variable patterns of collapse, especially at the tongue base, with the use of different sedative agents. A universally accepted classification scheme for drug-induced sleep endoscopy is lacking. A new DISE classification system, termed Palate, Tonsils, Lateral pharyngeal wall, Tongue base, Epiglottis, was introduced this year with the noted advantage of being able to better differentiate between clinically relevant tonsillar and lateral pharyngeal wall collapse. Despite recent advances in the field, there remains no general consensus that DISE findings predict surgical success but may aid in the identification of patients who will respond well to oral appliance therapy.

SUMMARY

Drug-induced sleep endoscopy is a structure-based evaluation of the upper airway that more closely resembles the natural sleep state compared with awake evaluation.

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.

Preoperative identification of children at high risk of obstructive sleep apnea

Obstructive sleep apnea is a common childhood disorder which can lead to serious health problems if left untreated. Enlarged adenoid and tonsils are the commonest causes, and adenotonsillectomy is the recommended first line of treatment. Obstructive sleep apnea poses as an anesthetic challenge, and it is a well-known risk factor for perioperative adverse events. The presence and severity of an obstructive sleep apnea diagnosis will influence anesthesia, pain management, and level of monitoring in recovery period. Preoperative obstructive sleep apnea assessment is necessary, and anesthetists are ideally placed to do so. Currently, there is no standardized approach to the best method of preoperative screening for obstructive sleep apnea. Focused history, clinical assessments, and knowledge regarding the strengths and limitations of available obstructive sleep apnea assessment tools will help recognize a child with obstructive sleep apnea in the preoperative setting.

Can drug-induced sleep endoscopy improve the success rates of tongue base surgery?

Background

The purpose of this study was to determine the therapeutic value of drug-induced sleep endoscopy (DISE) by comparing the outcomes of tongue base surgery based on Muller’s maneuver (MM) and those based on DISE in obstructive sleep apnea (OSA) patients.

Methods

Ninety-five patients who underwent the tongue base surgery in combination with palatal surgery for OSA at a tertiary referral hospital between March 2012 and March 2019 were enrolled in this retrospective comparative study. Forty-seven patients underwent MM for surgical decision and 48 patients underwent DISE in addition to MM for surgical decision. Surgical success was defined according to the Sher criteria (postoperative apnea-hypopnea index [AHI] < 20/h and ≥ 50% reduction in preoperative AHI), and AHI improvement (%) was defined as (preoperative AHI-postoperative AHI) × 100/preoperative AHI. For comparison between the MM and DISE groups, p-values were calculated using independent or paired t-tests for continuous variables and using chi-square test for categorical variables.

Results

By comparing the results of MM and DISE, consensus on the tongue base level showed insignificant concordance (kappa = 0.017, p = 0.865), whereas that on the oropharynx level showed fair agreement (kappa =0.241, p = 0.005). AHI, supine AHI, rapid eyeball movement (REM) AHI, non-REM AHI, and nadir oxygen saturation were all significantly improved after the tongue base surgery in both groups. The MM group showed a significant improvement in the Epworth sleepiness scale after the tongue base surgery (p = 0.014), whereas the DISE group did not (p = 0.165). However, there was no significant difference in the AHI improvement (MM group = 47.0 ± 32.0, DISE group = 48.3 ± 35.4, p = 0.852) and surgical success (MM group = 42.6%, DISE group = 45.8%, p = 0.748) between the groups. Tonsil grade (p < 0.05) and occlusion at the oropharynx lateral wall (p = 0.031) were significantly related to surgical success in the MM group.

Conclusions

In the judgment of the tongue base surgery, MM and DISE findings showed poor agreement. DISE might affect the surgical decision on the tongue base surgery in OSA patients; however, there was a lack of evidence regarding the superiority of DISE over MM with respect to the surgical outcomes.

Drug-Induced Sleep Endoscopy: Clinical Application and Surgical Outcomes

The visualization of the level and pattern of apnea and hypopnea events is of pivotal importance in the diagnosis and therapeutic decision-making for sleep-disordered breathing (SDB). There are numerous techniques available to assess upper airway obstruction, which include imaging, acoustic analysis, pressure transducer recording, and endoscopic evaluation. Drug-induced sleep endoscopy (DISE) is a diagnostic tool that allows the dynamic, three-dimensional evaluation of the patterns of vibration and collapse of the upper airway of SDB patients. DISE may change the initial surgical planning in a high percentage of cases. A universally accepted and methodologically standardized DISE could provide significant insight into its role to improve surgical outcomes. However, up to now the ideal DISE protocol remains an open question.

Increasing preoperative apnea severity improves upper airway stimulation response in OSA treatment

OBJECTIVE

Examine the patient characteristics of those undergoing upper airway stimulation (UAS) for the treatment of continuous positive airway pressure (CPAP)-refractive obstructive sleep apnea (OSA) at a tertiary care medical center to determine objective clinical predictors of success.

METHODS

Retrospective chart review of the first 25 consecutive patients between August 2015 and December 2016 treated with UAS at a tertiary care academic center. Demographic data, medical and sleep history, pre- and postoperative polysomnography data, and sleep endoscopy findings were collected. Statistical analysis was performed using two-sided t test with bivariate and linear regression analysis.

RESULTS

In our cohort of 25 patients, mean age was 67.5 ± 7.6 years, and mean body mass index (BMI) was 28.2 ± 3.8 kg/m2 with 42% female. One patient was excluded from analysis for unmasking of complete central apnea with therapy. AHI decreased by a mean of 33.8 events/hour following treatment (95% confidence interval: 25.8 to 41.7, P < 0.001). Preintervention AHI was associated with therapy response, with each point of preintervention AHI leading to an average decrease of 1.03 points (P < 0.001). Eighty-three percent of patients achieved a treatment AHI < 5, whereas 92% achieved an AHI < 10. Mean device use was 49.5 ± 10.4 hours per week. Ninety-two percent of patients were discharged the day of surgery. No major adverse events occurred.

CONCLUSION

UAS continues to gain popularity for the treatment of CPAP-refractive OSA; therefore, identification of predictors of success is crucial. Our study, although small, suggests that more severe preintervention AHI does not preclude significant therapy response and may expand the inclusion criteria for UAS, meriting further investigation.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:556-560, 2020.

Drug-induced sleep endoscopy-directed adenotonsillectomy in pediatric obstructive sleep apnea with small tonsils

The study aims to examine drug-induced sleep endoscopy (DISE) in the decision-making process of pediatric obstructive sleep apnea (OSA) patients with small tonsils. This was a retrospective study of children who underwent awake flexible endoscopy, DISE, and adenoidectomy with/without tonsillectomy at the Shanghai Children’s Medical Center between 03/2015 and 12/2016. Tonsillectomy was performed for tonsillar obstruction found by DISE. Adenoidectomy was performed for all children. Cardio-pulmonary coupling (CPC) and oximetry were observed before/after surgery. The study included 126 children: 56 (44.4%) with grade 2 tonsils and 70 (55.6%) with grade 1. Mean age was 5.7±3.2 (range, 2.8–10.4) years and mean BMI of 15.7±5.5 kg/m². Unexpectedly, DISE showed tonsillar obstruction in 57 (45.2%) children, including 44 (78.6%) with grade 2 tonsils and 13 (18.6%) with grade 1. Therefore, DISE-directed tonsillectomy was performed for 57 patients. There was an improvement in respiratory disturbance index (RDI) and oxygen saturation nadir in the DISE (P = 0.0007, P = 0.037) and control (P = 0.001, P = 0.023) groups 6 months after surgery, but RDI improvement was better in the DISE group compared with controls 1 year after surgery (P = 0.042). DISE is a good way to determine the necessity of tonsillectomy in pediatric OSA patients with small tonsils.

Is epiglottis surgery necessary for obstructive sleep apnea patients with epiglottis obstruction?

OBJECTIVES/HYPOTHESIS

To examine the effect of epiglottis obstruction during drug-induced sleep endoscopy (DISE) on the surgical results of multilevel sleep surgery without epiglottic intervention.

STUDY DESIGN

Cross-sectional study.

METHODS

This investigation involved patients diagnosed with severe obstructive sleep apnea (OSA) based on preoperative polysomnography (PSG), who underwent DISE followed by multilevel OSA surgery without epiglottic intervention at Kyung Hee Medical Center (Seoul, South Korea) between March 2013 and July 2016. During DISE, obstruction patterns of the upper airway were evaluated using the velum, oropharynx, tongue base, epiglottis classification method. Follow-up PSG was performed 3 months after surgery to determine the success rate of multilevel surgery without epiglottic intervention. A comparison was done between the group with epiglottis obstruction and the group without epiglottis obstruction.

RESULTS

Epiglottis obstruction was observed during DISE in 43.7% of patients. After application of exclusion criteria, 54 subjects were included (27 with and 27 without epiglottis obstruction). DISE revealed an association between epiglottis obstruction and tongue base collapse (P = .02). Comparing pre- and postoperative PSG findings, both groups exhibited improvement postoperatively. The success rate was 44.4% in the epiglottis obstruction group and 40.7% in the non-epiglottis obstruction group (P = .80). There was no difference in surgical success rates between the two groups.

CONCLUSIONS

The prevalence of epiglottis obstruction requiring epiglottic surgery was lower than what was found during DISE. Sleep surgeons may consider staged epiglottic surgery in patients with epiglottis obstruction.

LEVEL OF EVIDENCE

3b Laryngoscope, 129:2658-2662, 2019.

Drug-induced sleep endoscopy: the effect of different passive maneuvers on the distribution of collapse patterns of the upper airway in obstructive sleep apnea patients

PURPOSE

To evaluate the effect of different passive maneuvers (lateral head rotation and jaw thrust) during drug-induced sleep endoscopy (DISE) on distribution of collapse patterns at the level of velum, oropharynx, tongue base, and epiglottis (VOTE).

METHODS

Retrospective, single-center cohort study. Patients diagnosed with OSA who underwent DISE between August 2016 and February 2017 were included. During DISE procedure lateral head rotation, jaw thrust and a combination of both were applied and scored by VOTE obstruction level. Also, the effect of these maneuvers was analyzed for complete concentric collapse (CCC) versus complete non-concentric collapse (CNCC) subgroups.

RESULTS

Two hundred patients were included (161 male (80.5%), mean age 50.1 ± 11.7 years, median AHI 19.2 (11.7, 31.0) events/h). For lateral head rotation, significant improvement in upper airway collapse at all levels was observed, with exception of the level of the oropharynx, where an increase in obstruction was seen. Jaw thrust resulted in a significant decrease of collapse on all four VOTE levels. The CCC group responded similarly to the CNCC group when only one maneuver was applied, but the CCC group showed less improvement when both maneuvers were combined.

CONCLUSIONS

This study gives new insights into the changes in distribution of collapse patterns when passive maneuvers are applied during DISE. Jaw thrust and lateral head rotation gave improvement of obstruction mostly in line with previous research. The CNCC and CCC groups responded similarly to application of a single maneuver, but there was a significant difference found when both maneuvers were combined.

Predicting Success of Oral Appliance Therapy in Treating Obstructive Sleep Apnea Using Drug-Induced Sleep Endoscopy

STUDY OBJECTIVES

Oral appliance therapy (OAT) can be an effective treatment option for patients with obstructive sleep apnea unable to tolerate continuous positive airway pressure. We hypothesize that drug-induced sleep endoscopy (DISE) can be useful in identifying patients who will benefit from OAT.

METHODS

A retrospective review of all patients who underwent DISE (DISE group) between January 2014 and June 2016 was carried out. We included patients if they received OAT based on recommendations made by DISE findings. A control group was designed by selecting a sample of patients undergoing polysomnography (PSG) with an oral appliance in place who had not undergone prior DISE (no DISE group). The two cohorts were compared to evaluate the hypothesis.

RESULTS

A total of 20 patients fit inclusion criteria for the DISE group and 20 patients for the no DISE group. There was no difference between the DISE and no DISE cohorts with respect to mean age, sex, pre-OAT body mass index, post-OAT body mass index, or pre-OAT PSG characteristics including: apneahypopnea index (AHI), oxygen desaturation nadir, or Epworth Sleepiness Scale score. There was a significantly lower treatment AHI (P = .04) and increased number of patients reaching an AHI less than 5 events/h with OAT therapy (P = .04) in the DISE group.

CONCLUSIONS

Patients showing increased airway dimensions at the level of the velum and/or oropharynx with a jaw thrust may benefit the most from OAT. The use of DISE to identify this subset of patients is helpful in optimizing outcomes with OAT.

Low inter-examiner agreement of the Friedman staging system indicating limited value in patient selection

Purpose

The Friedman staging system is a clinical method for selecting patients with obstructive sleep apnoea who are likely to benefit from uvulopalatopharyngoplasty. The objective of this study was to evaluate the system by determining its inter-examiner agreement.

Methods

Twelve patients with obstructive sleep apnoea were examined by 14 doctors. The Friedman stage was derived from tonsil size and tongue position, and a Cohen’s kappa analysis was performed to assess inter-examiner agreement.

Results

One hundred and sixty-eight ratings were performed. The median kappa for tongue position was 0.32 (first and third quartiles: 0.21 and 0.44) and was 0.62 (0.50 and 0.63) for tonsil size. The median kappa for the Friedman stage was 0.38 (0.24 and 0.55), which corresponds to only a slight or fair agreement.

Conclusion

The Friedman staging system demonstrated a low inter-examiner agreement, indicating that the system is an uncertain method for selecting patients for uvulopalatopharyngoplasty.

Level of evidence

2B.

A review on drug-induced sedation endoscopy - Technique, grading systems and controversies

Sleep disordered breathing (SDB) comprises a spectrum of disorders, ranging from simple snoring to severe obstructive sleep apnoea (OSA), with a significant burden to health care systems in high income countries. If left untreated, OSA has significant cumulative, long-term health consequences. In the 1990s drug induced sedation endoscopy (DISE) has been developed to become a primary tool in the diagnosis and management of OSA. It allows meticulous endoscopic evaluation of the airway and identifies areas of collapse, thereby informing both on the selection of surgical techniques, where efficacy depends entirely on success at relieving obstruction at a certain level and on the usefulness of conservative measures, such as mandibular advancement splints. This article provides a review of the literature on DISE, covering different grading systems and techniques, explaining different rationales and discussing controversies.