Drug-induced sleep endoscopy in sleep-disordered breathing: report on 1,249 cases

Lingual tonsillectomy with palatal surgery for the treatment of obstructive sleep apnea in adults: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis to evaluate effects of lingual tonsillectomy with palatal surgery as a combined procedure for the treatment of obstructive sleep apnea (OSA) in adults.

SEARCH METHODS

Data source: a comprehensive search of MEDLINE, Scopus, Ovid, Web of Science, and the Cochrane Library was performed through November 2017. Manual searches and subject matter expert input were also obtained. This review includes studies assessing efficacy of lingual tonsillectomy with palatal surgery as a combined procedure for the treatment of OSA in adults, who had multilevel obstruction including lingual tonsil hypertrophy, in which apnea/hypopnea index (AHI) or respiratory disturbance index (RDI) were reported.

RESULTS

A total of four studies (107 patients) met our inclusion criteria. Pooled random effects analysis demonstrated a statistically significant improvement of polysomnographic respiratory events postoperatively, with average AHI reduction of 18.51 events per hour, [95% confidence interval (CI) (- 31.72, - 5.31); P = 0.006] and increase in minimal arterial oxygen saturation of 5.26 [95% CI (0.10, 10.42); P = 0.05]. The result also showed that the procedures significantly improved sleepiness resulting in an average Epworth Sleepiness Scale (ESS) reduction of 5.44 [95% CI (- 8.69, - 2.18); P = 0.001].

CONCLUSION

A combination of lingual tonsillectomy with palatal surgery may offer benefits in a selected group of OSA adults, in terms of apnea/hypopnea index, minimal arterial oxygen saturation and Epworth Sleepiness Scale. Data were based on meta-analysis of all case series with 2-6 months' follow-up.

Does drug-induced sleep endoscopy predict surgical success of limited palatal muscle resection in patients with obstructive sleep apnea?

OBJECTIVE

The aims of this study were to determine the associated factors affecting the success rate of limited palatal muscle resection (LPMR), and to investigate whether drug-induced sleep endoscopy (DISE) could predict the therapeutic response to LPMR in patients with obstructive sleep apnea obstructive sleep apnea (OSA).

METHODS

Twenty-one consecutive OSA patients underwent LPMR were enrolled. All patients received routine ENT examination, preoperative DISE, and polysomnography (PSG). Clinical, polysomnographic, cephalometric variables, and DISE findings were evaluated. The measurements were related to the success or failure of LPMR based on the results of preoperative and postoperative PSG.

RESULTS

The overall success rate of LPMR was 66.6%. Postoperative AHI and minimal oxygen saturation were significantly decreased after LPMR (p<0.001). Comparison between success and failure groups revealed no significant differences in BMI, Friedman stage, preoperative AHI, minimal oxygen saturation, and all cephalometric parameters. However, the success of LPMR was significantly correlated with site, degree, and configuration of obstruction in DISE. In the velopharynx, complete obstruction (p=0.006) with anterolateral or concentric pattern (p=0.044) had significantly better success rate than partial obstruction with lateral pattern.

CONCLUSION

DISE was only predictive method for identifying the success in OSA patients undergoing LPMR. Patients with anteroposterior or concentric total obstruction in the velopharynx might be suitable candidate for LPMR.

Hyoepiglottic ligament collagen and elastin fiber composition and changes associated with aging

OBJECTIVE

The epiglottis may contribute to upper airway obstruction in approximately 10% of patients with obstructive sleep apnea. Clinical experience indicates that older patients may be more likely to have epiglottis-related obstruction. This study was designed to examine tissue characteristics of the hyoepiglottic ligament as a possible factor in epiglottis-related obstruction based on previous research suggesting that older adults have fewer collagen, elastin, and muscle fibers in the hyoepiglottic ligament.

METHODS

This is a cross-sectional study of 25 human cadaver hyoepiglottic ligaments. Specimens were stained using Masson's trichrome and Picrosirius red for collagen fibers and with Verhoeff-Van Gieson for elastin fibers. Percentage of collagen and elastin fiber staining for each specimen was calculated and averaged over three regions of each ligament section. Regression analysis was used to determine the association between age, smoking history, and collagen and elastin composition of the hyoepiglottic ligament.

RESULTS

The average age of the specimens was 68.4 ± 15.1 years (range 30-90 years). Increasing age was associated with a lower percentage of collagen and elastin fibers. When accounting for tobacco use, each 1-year increase in age was associated with a 0.53% decrease in Masson's trichrome staining (P = 0.004), a 0.35% decrease in Picrosirius red staining (P = 0.023), and a 0.33% decrease in Verhoeff-Van Gieson staining (P = 0.008).

CONCLUSION

Increasing age is associated with decreases in the collagen and elastin content of the hyoepiglottic ligament.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:1245-1248, 2018.

Sleeping tongue: current perspectives of genioglossus control in healthy individuals and patients with obstructive sleep apnea

The focus of this review was on the genioglossus (GG) muscle and its role in maintaining upper airway patency in both healthy individuals and obstructive sleep apnea (OSA) patients. This review provided an overview of GG anatomy and GG control and function during both wakefulness and sleep in healthy individuals and in those with OSA. We reviewed evidence for the role of the GG in OSA pathogenesis and also highlighted abnormalities in GG morphology, responsiveness, tissue movement patterns and neurogenic control that may contribute to or result from OSA. We summarized the different methods for improving GG function and/or activity in OSA and their efficacy. In addition, we discussed the possibility that assessing the synergistic activation of multiple upper airway dilator muscles may provide greater insight into upper airway function and OSA pathogenesis, rather than assessing the GG in isolation.

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

Objective

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

Methods

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

Results

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

Conclusion

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

A retrospective study: does upper airway morphology differ between non-positional and positional obstructive sleep apnea?

Objective

The objective of this study was to explore the differences in upper airway morphology between positional (POSA) and non-positional (NPOSA) obstructive sleep apnea.

Methods

This retrospective study enrolled 75 patients (45 NPOSA and 30 POSA) who underwent polysomnography (PSG) and computed tomography (CT). The differences in, and relationships of, the PSG values and CT data between POSA and NPOSA were analyzed.

Results

Significant (p < 0.05) differences between the two groups were found in the apnea/hypopnea index (AHI), lateral-AHI (L-AHI), soft palate length (SPL), cross-sectional palatopharyngeal area, and the coronal diameter (CD) of the palatopharyngeal area at the narrowest part of the glossopharynx, which were all higher in POSA, except for SPL, AHI, and L-AHI. L-AHI was correlated with the cross-sectional area (r =  − 0.306, p = 0.008) and CD (r =  − 0.398, p < 0.001) of the palatopharyngeal area, the cross-sectional area (r =  − 0.241, p = 0.038) and CD (r =  − 0.297, p = 0.010) of the narrowest level of the glossopharynx, the CD of the glossopharynx (r = 0.284, p = 0.013), body mass index (BMI, r = 0.273, p = 0.018), SPL (r = 0.284, p = 0.014), and vallecula-tip of tongue (r = 0.250, p = 0.030). The SPL and CD at the narrowest part of the glossopharynx were included in the simplified screening model.

Conclusions

In NPOSA, the CD of the upper airway was smaller, and the soft palate was longer, than in POSA. These differences may play significant roles in explaining the main differences between NPOSA and POSA.

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

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

Predicting epiglottic collapse in patients with obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is characterised by pharyngeal obstruction occurring at different sites. Endoscopic studies reveal that epiglottic collapse renders patients at higher risk of failed oral appliance therapy or accentuated collapse on continuous positive airway pressure. Diagnosing epiglottic collapse currently requires invasive studies (imaging and endoscopy). As an alternative, we propose that epiglottic collapse can be detected from the distinct airflow patterns it produces during sleep.23 OSA patients underwent natural sleep endoscopy. 1232 breaths were scored as epiglottic/nonepiglottic collapse. Several flow characteristics were determined from the flow signal (recorded simultaneously with endoscopy) and used to build a predictive model to distinguish epiglottic from nonepiglottic collapse. Additionally, 10 OSA patients were studied to validate the pneumotachograph flow features using nasal pressure signals.Epiglottic collapse was characterised by a rapid fall(s) in the inspiratory flow, more variable inspiratory and expiratory flow and reduced tidal volume. The cross-validated accuracy was 84%. Predictive features obtained from pneumotachograph flow and nasal pressure were strongly correlated.This study demonstrates that epiglottic collapse can be identified from the airflow signal measured during a sleep study. This method may enable clinicians to use clinically collected data to characterise underlying physiology and improve treatment decisions.

Computed Tomography Characterization and Comparison With Polysomnography for Obstructive Sleep Apnea Evaluation

PURPOSE

We hypothesized that computed tomography (CT) combined with portable polysomnography (PSG) might better visualize anatomic data related to obstructive sleep apnea (OSA). The present study evaluated the CT findings during OSA and assessed their associations with the PSG data and patient characteristics.

PATIENTS AND METHODS

We designed a prospective cross-sectional study of patients with OSA. The patients underwent scanning during the awake state and apneic episodes. Associations of the predictor variables (ie, PSG data, respiratory disturbance index [RDI]), patient characteristics (body mass index [BMI], neck circumference [NC], and waist circumference [WC]), and outcome variables (ie, CT findings during apneic episodes) were assessed using logistic regression analysis. The CT findings during apneic episodes were categorized regarding the level of obstruction, single level (retropalatal [RP] or retroglossal [RG]) or multilevel (mixed RP and RG), degree of obstruction (partial or complete), and pattern of collapse (complete concentric collapse [CCC] or other patterns).

RESULTS

A total of 58 adult patients with OSA were scanned. The mean ± standard deviation for the RDI, BMI, NC, and WC were 41.6 ± 28.55, 27.80 ± 5.43 kg/m², 38.3 ± 4.3 cm, and 93.8 ± 13.6 cm, respectively. No variables distinguished between the presence of single- and multilevel airway obstruction in the present study. A high RDI (≥30) was associated with the presence of complete obstruction and CCC (odds ratio 6.33, 95% confidence interval 1.55 to 25.90; and odds ratio 3.77, 95% confidence interval 1.02 to 13.91, respectively) compared with those with a lesser RDI.

CONCLUSIONS

An increased RDI appears to be an important variable for predicting the presence of complete obstruction and CCC during OSA. Scanning during apneic episodes, using low-dose volumetric CT combined with portable PSG provided better anatomic and pathologic findings of OSA than did scans performed during the awake state.

Patterns of Upper Airway Obstruction on Drug-Induced Sleep Endoscopy in Patients with Sleep-Disordered Breathing with AHI <5

Objective

To describe the patterns of upper airway obstruction in patients with sleep-disordered breathing with apnea-hypopnea index (AHI) <5 using drug-induced sleep endoscopy (DISE).

Study Design

Retrospective study.

Setting

Tertiary care center.

Subjects and Methods

Inclusion of patients with sleep-disordered breathing with AHI <5 on polysomnography who underwent DISE. Patients <18 years of age were excluded. DISE findings were reported with the VOTEL classification system: the level of collapse was described as occurring at the velum, oropharynx, tongue base, epiglottis, and the lingual tonsils. The degree of collapse was reported as complete, partial, or none. The pattern of the obstruction was described as anteroposterior, lateral, or concentric when applicable.

Results

A total of 54 patients with sleep-disordered breathing with AHI <5 underwent DISE. Ages ranged from 19 to 65 years. DISE was performed alone in 7% (n = 4) of patients and in conjunction with surgery in 93% (n = 50) of patients. The velum was the most frequent site of upper airway obstruction (85%, n = 46), followed by base of tongue (63%, n = 34), epiglottis (39%, n = 21), lingual tonsils (35%, n = 19), and oropharynx (31%, n = 17). Eighty-three percent (n = 45) of patients had multiple levels of upper airway obstruction, and 15% (n = 8) had a single level of upper airway obstruction.

Conclusion

Patients with sleep-disordered breathing with AHI <5 have significant upper airway obstruction as seen on DISE. DISE findings indicate that a majority of these patients have multiple levels of upper airway obstruction, which can lead to significant symptoms.

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.

Effect of Sleeping Position on Upper Airway Patency in Obstructive Sleep Apnea Is Determined by the Pharyngeal Structure Causing Collapse

Objectives

In some patients, obstructive sleep apnea (OSA) can be resolved with improvement in pharyngeal patency by sleeping lateral rather than supine, possibly as gravitational effects on the tongue are relieved. Here we tested the hypothesis that the improvement in pharyngeal patency depends on the anatomical structure causing collapse, with patients with tongue-related obstruction and epiglottic collapse exhibiting preferential improvements.

Methods

Twenty-four OSA patients underwent upper airway endoscopy during natural sleep to determine the pharyngeal structure associated with obstruction, with simultaneous recordings of airflow and pharyngeal pressure. Patients were grouped into three categories based on supine endoscopy: Tongue-related obstruction (posteriorly located tongue, N = 10), non-tongue related obstruction (collapse due to the palate or lateral walls, N = 8), and epiglottic collapse (N = 6). Improvement in pharyngeal obstruction was quantified using the change in peak inspiratory airflow and minute ventilation lateral versus supine.

Results

Contrary to our hypothesis, patients with tongue-related obstruction showed no improvement in airflow, and the tongue remained posteriorly located while lateral. Patients without tongue involvement showed modest improvement in airflow (peak flow increased 0.07 L/s and ventilation increased 1.5 L/min). Epiglottic collapse was virtually abolished with lateral positioning and ventilation increased by 45% compared to supine position.

Conclusions

Improvement in pharyngeal patency with sleeping position is structure specific, with profound improvements seen in patients with epiglottic collapse, modest effects in those without tongue involvement and-unexpectedly-no effect in those with tongue-related obstruction. Our data refute the notion that the tongue falls back into the airway during sleep via gravitational influences.

Airflow Shape Is Associated With the Pharyngeal Structure Causing OSA

BACKGROUND

OSA results from the collapse of different pharyngeal structures (soft palate, tongue, lateral walls, and epiglottis). The structure involved in collapse has been shown to impact non-CPAP OSA treatment. Different inspiratory airflow shapes are also observed among patients with OSA. We hypothesized that inspiratory flow shape reflects the underlying pharyngeal structure involved in airway collapse.

METHODS

Subjects with OSA were studied with a pediatric endoscope and simultaneous nasal flow and pharyngeal pressure recordings during natural sleep. The mechanism causing collapse was classified as tongue-related, isolated palatal, lateral walls, or epiglottis. Flow shape was classified according to the degree of negative effort dependence (NED), defined as the percent reduction in inspiratory flow from peak to plateau.

RESULTS

Thirty-one subjects with OSA (mean apnea-hypopnea index score ± SD, 54 ± 27 events/h) who were 50 ± 9 years of age were studied. NED was associated with the structure causing collapse (P < .001). Tongue-related obstruction (n = 13) was associated with a small amount of NED (median, 19; interquartile range [IQR], 14%-25%). Moderate NED was found among subjects with isolated palatal collapse (median, 45; IQR, 39%-52%; n = 8) and lateral wall collapse (median, 50; IQR, 44%-64%; n = 8). The epiglottis was associated with severe NED (median, 89; IQR, 78%-91%) and abrupt discontinuities in inspiratory flow (n = 9).

CONCLUSIONS

Inspiratory flow shape is influenced by the pharyngeal structure causing collapse. Flow shape analysis may be used as a noninvasive tool to help determine the pharyngeal structure causing collapse.

Hyoid myotomy and suspension without simultaneous palate or tongue base surgery for obstructive sleep apnea

Objective

Determine the effects of hyoid myotomy and suspension (HMS) without concurrent palatal or tongue base sleep surgery for obstructive sleep apnea (OSA).

Method

Patients with OSA treated with HMS were identified using CPT code (21685) at an academic and private sleep surgery clinic. Those who underwent concurrent palatal or tongue base sleep surgery were excluded. Outcomes included simultaneous procedures, apnea-hypopnea index (AHI), lowest oxyhemoglobin saturation (LSAT), and Epworth Sleepiness Scale (ESS).

Results

Nineteen patients with OSA underwent HMS without palatal or tongue base sleep surgery. The average age at surgery was (55.3 ± 13.5) years with a majority of patients being male (71%). Concurrent procedures included the following: torus mandibularis excision (n = 1), endoscopic sinus surgery (n = 4), septoplasty (n = 10), inferior turbinate reduction (n = 12), and nasal valve repair (n = 2). AHI improved significantly from (39.7 ± 21.2) events/h to (22.6 ± 22.7) events/h after HMS (P < 0.01), which represented a 43% reduction. LSAT significantly increased from (82.2% ± 9.9%) to (86.6% ± 6.2%), P < 0.01. There was no improvement in ESS after surgery (8.2 ± 4.4) to (8.3 ± 5.2), P = 0.904. A subset of patients with severe OSA (AHI > 30 events/h) had an improvement in AHI from (49.9 ± 16.6) events/h to (29.1 ± 24.9) events/h, P < 0.01.

Conclusion

HMS without palatal or tongue base sleep surgery improves OSA severity. It can be considered as a valid option in the treatment of OSA in appropriately-selected patients.

[Drug-induced sedation endoscopy-quo vadis? : Review and outlook]

BACKGROUND

Drug-induced sedation endoscopy (DISE) is a diagnostic procedure which allows evaluation of the collapsibility of the upper airway. According to expert opinion, it is possible to imitate nocturnal collapsibility and perform a realistic investigation of the site of obstruction and vibration. This should enable sufficient and precise therapeutic advice to be given solely on the basis of clinical assessment.

OBJECTIVE

The current publication critically evaluates the present state of development of DISE and its potential indications.

MATERIALS AND METHODS

A PubMed literature research was performed using "sleep" and "endoscopy" or "DISE" as keywords. Relevant publications were evaluated.

RESULTS

The present publication provides a historical summary of the available publications and relates these to other methods for examining obstructive sleep apnea. The present state of DISE in terms of drugs applied, grading systems, and validity is evaluated. Indications for DISE are described and critically discussed on the basis of literature data.

CONCLUSION

DISE provides deep insights into the genesis of obstructions of the upper airway and snoring. Although its value for diagnosis and treatment of sleep-disordered breathing could not yet be demonstrated for all non-CPAP (continuous positive airway pressure) therapies, DISE could identify predictive parameters some methods. Further potential indications for DISE might be predictive examinations for mandibular advancement devices and respiration-synchronous neurostimulation of the hypoglossal nerve. DISE will thus remain a valuable diagnostic tool for obstructive sleep apnea and rhonchopathy.

Drug-Induced Sleep Endoscopy Changes the Treatment Concept in Patients with Obstructive Sleep Apnoea

The present study evaluated whether drug-induced sleep endoscopy (DISE) helps identify the site of obstruction in patients with obstructive sleep apnoea (OSA). A total of 51 consecutive patients with polysomnography-confirmed OSA were enrolled in this prospective study. The presumed site of obstruction was determined according to history, otorhinolaryngologic examination, and polysomnography and a therapeutic plan designed before DISE. In 11 patients with severe OSA and/or previously failed continuous positive airway pressure (CPAP) treatment, DISE with simultaneous CPAP was performed. Multilevel collapse was noted in 49 patients (96.1%). The most frequent multilevel collapse was palatal, oropharyngeal, and tongue base collapse (n = 17, 33.3%), followed by palatal and oropharyngeal collapse (n = 12, 23.5%). Pathology of the larynx (epiglottis) was observed in 16 patients (31.4%). The laryngeal obstruction as a reason for intolerance of CPAP was observed in 3/11 (27.3%) patients. After DISE, the surgical plan was changed in 31 patients (60.8%). The results indicate that DISE helps identify the site of obstruction in the upper airways in patients with OSA more accurately and that the larynx plays an important role in OSA.

Drug-Induced Sleep Endoscopy (DISE) with Target Controlled Infusion (TCI) and Bispectral Analysis in Obstructive Sleep Apnea

The aim of this study was to establish a standardized protocol for drug-induced sleep endoscopy (DISE) to differentiate obstruction patterns in obstructive sleep apnea (OSA). Target-controlled infusion (TCI) of the sedative propofol was combined with real-time monitoring of the depth of sedation using bispectral analysis. In an observational study 57 patients (mean age 44.8 years, ± SD 10.5; mean apnea hypopnea Index (AHI) 30.8/hr, ± SD 21.6, mean BMI 28.2 kg/m2, ± SD 5.3) underwent cardiorespiratory polysomnography followed by DISE with TCI and bispectral analysis. Sleep was induced solely by the intravenous infusion of propofol with a TCI-pump, with an initial target plasma level of 2.0 µg/ml. Under continuous monitoring of the patient's respiration, state of consciousness and value of the bispectral analysis, the target plasma propofol level was raised in steps of 0.2 µg/ml/2 min until the desired depth of sedation was reached. The mean value of the bispectral analysis at the target depth of sedation was determined and the obstruction patterns during DISE-TCI-bispectral analysis then classified according to the VOTE-system. Subsequently the results were analyzed according to polysomnographic and anthropometric data. The occurrence of multilevel obstruction sites across all degrees of severity of OSA clarifies the need for sleep endoscopy prior to upper airway surgery. The advantage of this technique is the reproducibility of the protocol even for heterogeneous groups of patients. In addition, the gradual controlled and standardized increase of the plasma level of propofol with real-time control of the bispectral index leads to a precisely controllable depth of sedation. The DISE-TCI-bispectral analysis procedure is a step towards a required reproducible protocol of sleep endoscopy - capable of standardization. However it is not yet known whether these observed obstruction patterns also correspond to findings in natural sleep.

Does drug-induced sleep endoscopy predict surgical success in transoral robotic multilevel surgery in obstructive sleep apnea?

OBJECTIVES/HYPOTHESIS

The aim of this study was to determine if drug-induced sleep endoscopy (DISE) was predictive of success for patients undergoing transoral robotic surgery (TORS) and multilevel procedures for sleep apnea.

STUDY DESIGN

Retrospective case series of patients who underwent TORS surgery for sleep apnea METHODS: Before and after polysomnograms were analyzed to assess improvement, success, and cure. Improvement was defined as any decrease in apnea-hypopnea index (AHI), success as an AHI <20 with a decrease >50%, and cure as an AHI <5. DISE videos were scored using the NOHL (nose, oropharynx, hypopharynx, larynx) and VOTE (velum, oropharynx, tongue, epiglottis) classification systems.

RESULTS

One hundred one patients were available for analysis. Eighty-seven percent of patients had an improvement in their AHI. Fifty-one percent met criteria for success, whereas 17% were cured. The degree of collapse at individual NOHL and VOTE subsites as well as total additive scores did not predict improvement, success, or cure. Patients with no oropharyngeal lateral collapse in the VOTE classification system were more likely to improve following surgery (P = .001); however, this effect did not hold for success or cure. Multivariate analysis of DISE variables was not predictive of success.

CONCLUSIONS

In obstructive sleep apnea patients, there is a 51% success rate and a 17% cure rate. DISE, as scored by the NOHL and VOTE system, did not readily identify patients who would benefit most from surgery. Patients with lateral oropharyngeal collapse may be poorer candidates. Prospective, larger studies are required to further evaluate the use of DISE in predicting success following TORS.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:971-976, 2017.

Phenotypes in obstructive sleep apnea: A definition, examples and evolution of approaches

Obstructive sleep apnea (OSA) is a complex and heterogeneous disorder and the apnea hypopnea index alone can not capture the diverse spectrum of the condition. Enhanced phenotyping can improve prognostication, patient selection for clinical trials, understanding of mechanisms, and personalized treatments. In OSA, multiple condition characteristics have been termed "phenotypes." To help classify patients into relevant prognostic and therapeutic categories, an OSA phenotype can be operationally defined as: "A category of patients with OSA distinguished from others by a single or combination of disease features, in relation to clinically meaningful attributes (symptoms, response to therapy, health outcomes, quality of life)." We review approaches to clinical phenotyping in OSA, citing examples of increasing analytic complexity. Although clinical feature based OSA phenotypes with significant prognostic and treatment implications have been identified (e.g., excessive daytime sleepiness OSA), many current categorizations lack association with meaningful outcomes. Recent work focused on pathophysiologic risk factors for OSA (e.g., arousal threshold, craniofacial morphology, chemoreflex sensitivity) appears to capture heterogeneity in OSA, but requires clinical validation. Lastly, we discuss the use of machine learning as a promising phenotyping strategy that can integrate multiple types of data (genomic, molecular, cellular, clinical) to identify unique, meaningful OSA phenotypes.

Positional therapy in patients with residual positional obstructive sleep apnea after upper airway surgery

PURPOSE/BACKGROUND

A considerable portion of patients has residual positional obstructive sleep apnea (POSA) after upper airway surgery. Those patients could benefit from additional treatment with positional therapy (PT). The objective of this prospective study was to assess the additional effect of PT in patients with residual POSA after upper airway surgery for sleep apnea.

METHODS

A polysomnography (PSG) was used to diagnose a patient with residual POSA after surgery. After informed consent, patients were treated with PT for 3 months and underwent a follow-up PSG while using the sleep position trainer (SPT). Changes in apnea-hypopnea index (AHI) and sleep position parameters were analyzed. Compliance rates and mean disease alleviation (MDA) were determined.

RESULTS

Thirty-three patients with a median postoperative AHI of 18.3/h sleep were included. With the SPT median AHI dropped to 12.5/h sleep and the Epworth Sleepiness Scale (ESS) improved from 10.0 to 7.0. After 3 months, 37.5 % patients were considered responders of whom 31.3 % had treatment success. The compliance rate with SPT was 89.0 %. MDA was 44.7 % for SPT alone. With the combination of both surgery and SPT, MDA was 65.6 %.

CONCLUSIONS

The results of this study indicate that additional PT in a complex OSA patient population with residual POSA after surgery can increase overall therapeutic effectiveness by improving the median MDA from 39.5 % (effect of surgery alone) to 65.6 % (effect of combining surgery and PT).

Airway Obstruction during Drug-Induced Sleep Endoscopy Correlates with Apnea-Hypopnea Index and Oxygen Nadir in Children

Objective

To determine if standardized intraoperative scoring of anatomic obstruction in children with obstructive sleep apnea correlates with the apnea-hypopnea index (AHI) and lowest oxygen saturation on preprocedural polysomnogram (PSG). A secondary objective was to determine if age, presence of a syndrome, or previous adenotonsillectomy affect this correlation.

Study Design

Case series with chart review.

Setting

Two tertiary care children’s hospitals.

Subjects

Patients with a preprocedural PSG who underwent drug-induced sleep endoscopy (DISE) over a 4-year period.

Methods

All DISEs were graded in a systematic manner with the Chan-Parikh (C-P) scoring system. AHI and nadir oxygen saturations were extracted from preprocedural PSG. Data were analyzed with a multivariate linear regression model that controlled for age at time of sleep endoscopy, syndrome diagnosis, and previous adenotonsillectomy.

Results

A total of 127 children underwent PSG prior to DISE: 56 were syndromic, and 21 had a previous adenotonsillectomy. Mean AHI was 13.6 ± 19.6 (± SD), and mean oxygen nadir was 85.4% ± 9.4%. Mean C-P score was 5.9 ± 2.7. DISE score positively correlated with preoperative AHI ( r = 0.36, P < .0001) and negatively correlated with oxygen nadir ( r = −0.26, P = .004). The multivariate linear regression models estimated that for every 1-point increase in C-P score, there is a 2.6-point increase in AHI (95% confidence interval: 1.4-3.8, P < .001) and a 1.1% decrease in the lowest oxygen saturation (95% confidence interval: –1.7 to −0.6, P < .001).

Conclusion

The C-P scoring system for pediatric DISE correlates with both AHI and lowest oxygen saturation on preprocedural PSG.

State of the art transoral robotic surgery for obstructive sleep apnea-hypopnea syndrome

Objective

To review the existing literature on the role of transoral robotic surgery (TORS) for tongue base reduction in the management of adult obstructive sleep apnea-hypopnea syndrome (OSAHS).

Methods

We searched PubMed, MEDLINE, and Scopus databases from the first literature report of this surgical technique to July 30, 2015 for studies investigating the use of TORS for tongue base reduction in treating adult OSAHS. Our primary outcome measures were Apnea– Hypopnea Index (AHI), lowest oxygen saturation (LSAT), Epworth Sleepiness Score (ESS), and the rates of surgical cure (AHI<5) and success (50% reduction in AHI accompanied by a postoperative AHI<20). Our secondary outcome measures were the volume of tissue resected and correlation to AHI, polysomnographic parameters, subjective outcomes, and body mass index. Complications of surgery were also analyzed.

Results

Thirteen articles were critically evaluated for this research. However, only four case series qualified for statistical analysis of postoperative polysomnographic outcomes and six case series for analysis of postoperative complications. They were case series with a total of 451 adult patients. Pooled analysis revealed statistically significant improvements in AHI, LSAT, and ESS after surgery by 26.83/hour, 5.28% and −8.03, respectively. The average rates of surgical cure and success were 23.8% and 66.7%, respectively. No study reported any deaths or complications related to the use of robotic equipment. The major complication rate was 6.9%, and the minor complication rate was 30.0%. Major complications included major bleeding (2.9%), severe odynophagia with dehydration (3.3%), and oropharyngeal stenosis (0.7%). Minor complications included transient bleeding (0.5%), transient dysphagia (3.8%), and dysgeusia (6.6%).

Conclusion

TORS for tongue base reduction, as a component of multilevel surgery, is an effective treatment option for OSAHS with an acceptable morbidity. This conclusion is based on the analysis of the results of multiple case series. Future studies should entail prospective randomized controlled trials with larger sample size for longer follow-up period.

Drug-induced sleep endoscopy in the obstructive sleep apnea: comparison between NOHL and VOTE classifications

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete collapse of the pharynx that result in a decrease in oxyhemoglobin saturation. Nasofibrolaryngoscopy under induced sleep is a promising alternative for identifying sites of upper airway obstruction in patients with OSA. This study aimed to compare the obstruction sites screened by drug-induced sleep endoscopy (DISE) using the Nose oropharynx hypopharynx and larynx (NOHL) and Velum oropharynx tongue base epiglottis (VOTE) classifications. We also determined the relationship between OSA severity and the number of obstruction sites and compared the minimum SaO₂ levels between DISE and polysomnography (PSG). This was a prospective study in 45 patients with moderate and severe OSA using DISE with target-controlled infusion of propofol bispectral index (BIS) monitoring. The retropalatal region was the most frequent obstruction site, followed by the retrolingual region. Forty-two percent of patients had obstruction in the epiglottis. Concentrically shaped obstructions were more prevalent in both ratings. The relationship between OSA severity and number of obstruction sites was significant for the VOTE classification. Similar minimum SaO₂ values were observed in DISE and PSG. The VOTE classification was more comprehensive in the analysis of the epiglottis and pharynx by DISE and the relationship between OSA severity and number of affected sites was also established by VOTE. The use of BIS associated with DISE is a reliable tool for the assessment of OSA patients.

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

OBJECTIVE

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

STUDY DESIGN

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

SETTING

Twenty-two participating institutions of the STAR trial.

SUBJECTS AND METHOD

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

RESULTS

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

CONCLUSION

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

Novel Surgical Approaches for the Treatment of Obstructive Sleep Apnea

Novel approaches to upper airway anatomic phenotyping, more reconstructive upper airway surgical techniques, and new implantable hypoglossal neurostimulation technology have very favorable potential to improve symptoms and quality-of-life measures, to reduce obstructive sleep apnea (OSA) disease severity and associated cardiovascular risk, and to serve as an adjunct to continuous positive airway pressure, oral appliances, and other forms of OSA medical therapy. Successful surgical therapy depends critically on accurate diagnosis, skillful knowledge and examination of the upper airway anatomy, proper procedure selection, and proficient technical application.

Nasal Expiratory Positive Airway Pressure Devices (Provent) for OSA: A Systematic Review and Meta-Analysis

Objective. To quantify the effectiveness of nasal expiratory positive airway pressure (nasal EPAP) devices or Provent as treatment for obstructive sleep apnea (OSA). Methods. PubMed and six other databases were searched through November 15, 2015, without language limitations. Results. Eighteen studies (920 patients) were included. Pre- and post-nasal EPAP means ± standard deviations (M ± SD) for apnea-hypopnea index (AHI) in 345 patients decreased from 27.32 ± 22.24 to 12.78 ± 16.89 events/hr (relative reduction = 53.2%). Random effects modeling mean difference (MD) was −14.78 events/hr [95% CI −19.12, −10.45], p value < 0.00001. Oxygen desaturation index (ODI) in 247 patients decreased from 21.2 ± 19.3 to 12.4 ± 14.1 events/hr (relative reduction = 41.5%, p value < 0.00001). Lowest oxygen saturation (LSAT) M ± SD improved in 146 patients from 83.2 ± 6.8% to 86.2 ± 11.1%, MD 3 oxygen saturation points [95% CI 0.57, 5.63]. Epworth Sleepiness Scale (ESS) M ± SD improved (359 patients) from 9.9 ± 5.3 to 7.4 ± 5.0, MD −2.5 [95% CI −3.2, −1.8], p value < 0.0001. Conclusion. Nasal EPAP (Provent) reduced AHI by 53.2%, ODI by 41.5% and improved LSAT by 3 oxygen saturation points. Generally, there were no clear characteristics (demographic factors, medical history, and/or physical exam finding) that predicted favorable response to these devices. However, limited evidence suggests that high nasal resistance could be associated with treatment failure. Additional studies are needed to identify demographic and polysomnographic characteristics that would predict therapeutic success with nasal EPAP (Provent).

A comparison of dexmedetomidine versus propofol during drug-induced sleep endoscopy in sleep apnea patients

OBJECTIVES/HYPOTHESIS

In this study, we compared the effects of propofol and dexmedetomidine on the upper airway collapse pattern and cardiopulmonary parameters of patients with obstructive sleep apnea (OSA) undergoing drug-induced sleep endoscopy (DISE).

STUDY DESIGN

Prospective, single center, observational study

MATERIALS AND METHODS

The 50 patients with OSA underwent 30 minutes of DISE on 2 different days, the first time with propofol target-controlled infusion (TCI) and the second time with dexmedetomidine TCI. Both the characteristics of upper airway obstruction and cardiopulmonary parameters in response to the depth of sedation achieved with each drug were evaluated.

RESULTS

The results obtained with propofol and dexmedetomidine DISE were in excellent agreement for all sites of obstruction irrespective of the depth of sedation. Although partial or total obstruction at all areas was consistently observed using both drugs, the degree of upper airway narrowing was slightly lower with dexmedetomidine than with propofol. However, the percentage of patients with a greater than 20% change in blood pressure and heart rate compared to baseline was significantly higher in response to propofol than to dexmedetomidine (P = 0.003 and P < 0.001, respectively). Minimal oxygen saturation was significantly lower in DISE with propofol than with dexmedetomidine (P = 0.004). The percentage of patients with oxygen saturation less than 90% or 80% during DISE was significantly higher in response to propofol than to dexmedetomidine (P = 0.032 and P < 0.001, respectively).

CONCLUSION

The DISE findings achieved with propofol and dexmedetomidine were in excellent agreement. However, during DISE, dexmedetomidine provided greater hemodynamic stability and less respiratory depression than propofol.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:763-767, 2016.

Awake examination versus DISE for surgical decision making in patients with OSA: A systematic review

OBJECTIVE

Traditionally, upper airway examination is performed while the patient is awake. However, in the past two decades, drug-induced sleep endoscopy (DISE) has been used as a method of tridimensional evaluation of the upper airway during pharmacologically induced sleep. This study aimed to systematically review the evidence regarding the usefulness of DISE compared with that of traditional awake examination for surgical decision making in patients with obstructive sleep apnea (OSA).

DATA SOURCES

Scopus, PubMed, and Cochrane Library databases were searched.

REVIEW METHODS

Only studies with a primary objective of evaluating the usefulness of DISE for surgical decision making in patients with OSA were selected. The included studies directly compared awake examination data with DISE outcome data in terms of possible influences on surgical decision making and operation success.

RESULTS

A total of eight studies with 535 patients were included in this review. Overall, the surgical treatment changed after DISE in 50.24% (standard deviation 8.4) cases. These changes were more frequently associated with structures contributing to hypopharyngeal or laryngeal obstruction. However, these differences do not automatically indicate a higher success rate.

CONCLUSION

This review emphasized the direct impact of DISE compared with that of awake examination on surgical decision making in OSA patients. However, it is also clear that the available published studies lack evidence on the association between this impact and surgical outcomes. Laryngoscope, 126:768-774, 2016.

Drug-induced sedation endoscopy versus clinical exploration for the diagnosis of severe upper airway obstruction in OSAHS patients

BACKGROUND

Identifying the sites of obstruction of the upper airway in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) is paramount for surgical planning. The aim of this study is to compare wake physical exam findings to the ones obtained during drug-induced sedation endoscopy (DISE) in the diagnosis of severe collapse of the upper airway in OSAHS patients.

METHODS

A retrospective chart review of OSAHS patients who underwent DISE at our institution during the 2006-2010 period was conducted. All the patients had previously undergone a physical examination that included modified Mallampati index (MMI), the Müller maneuver (MM), and the Friedman staging system. Level and severity of airway collapse were evaluated. A severe collapse was attributed to obstructions equal or greater than 75 % of the airway.

RESULTS

A total of 138 patients were included in the study. The incidence of severe airway collapse was compared between DISE and MM; at retropalatal level, no significant difference was found. At retrolingual level, 69 % of patients had severe collapse with DISE in comparison to a 28 % with the MM (p < 0.05). No relationship was found either with the MMI or with the Friedman staging system when compared to the incidence of severe retrolingual collapse diagnosed by DISE. Concordance was low between awake and DISE exploration in both retropalatal and retroglossal level.

CONCLUSION

The Müller maneuver underestimates tongue base severe obstruction diagnosis when compared to that obtained after DISE in OSAHS patients. The wake patient exploration does not accurately correlate to DISE exploration.

Transverse Retropalatal Collapsibility Is Associated with Obstructive Sleep Apnea Severity and Outcome of Relocation Pharyngoplasty

OBJECTIVE

The aim of this study was to investigate whether the retropalatal airway shape and collapsibility defined by awake nasopharyngoscopy with Müller's maneuver were associated with apnea-hypopnea index (AHI), positional dependency, and surgical outcome of relocation pharyngoplasty in patients with obstructive sleep apnea.

STUDY DESIGN

Case series with planned data collection.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

A total of 45 obstructive sleep apnea patients were included who underwent conservative treatment (n = 13) or relocation pharyngoplasty (n = 32), and their baseline and postoperative polysomnographies and awake nasopharyngoscopies with Müller's maneuver were reviewed. Shape ratio (transverse diameter [TD] / longitudinal diameter [LD]) in the stationary and Müller's phases and collapsibility (ColTD and ColLD) of the airway at the level of the uvular base were measured with a picture archiving and communication system. Intra- and interrater reliabilities were assessed. Associations among nasopharyngoscopic measurements, AHI, positional dependency, and surgical success (defined as a reduction of AHI ≥50% and a postoperative AHI ≤20/h) were statistically analyzed.

RESULTS

Reliability tests indicated substantial agreements of all nasopharyngoscopic measurements between raters and within raters. A higher baseline ColTD was significantly associated with an elevated AHI (r = 0.49, P = .001), whereas a lower postoperative ColTD was significantly related to surgical success (r = -0.38, P = .034). Nasopharyngoscopic findings were not statistically significantly correlated with positional dependency.

CONCLUSION

Transverse retropalatal collapsibility measured by awake nasopharyngoscopy with Müller's maneuver helps to predict individuals with moderate to severe sleep apnea and surgical outcome.

Association between Drug-Induced Sleep Endoscopy and Measures of Sleep Apnea Burden

OBJECTIVE

To test the following associations: (1) complete obstruction on drug-induced sleep endoscopy (DISE) and polysomnographic and subjective measures of obstructive sleep apnea; (2) tongue base/epiglottic obstruction and apnea index.

STUDY DESIGN

Retrospective cohort.

SETTING

Academic medical center.

SUBJECTS AND METHODS

Subjects included surgically naïve adult patients with DISE. Chart extraction included demographics, polysomnography, and Epworth Sleepiness Scale and SNORE25 (Symptoms of Nocturnal Obstruction and Related Events 25) scores. Each DISE video was examined for complete obstruction at velum, oropharynx, tongue, epiglottis (VOTE system). Student's t test, correlation, and multivariate linear regression were performed.

RESULTS

Among 65 subjects, complete obstruction was observed at 0 (3%), 1 (46%), 2 (48%), and 3 (3%) subsites, respectively. Subjects with 0-1 subsites vs 2-4 subsites of complete obstruction had similar apnea indexes (13 ± 24 vs 12 ± 17, P = .78, 83% power to detect difference of 15), apnea-hypopnea indexes (30 ± 25 vs 31 ± 28, P = .96, 54% power to detect difference of 15), Epworth Sleepiness Scale scores (11 ± 7 vs 12 ± 5, P = .34, 91% power to detect difference of 5), and SNORE25 scores (2.0 ± 1.1 vs 1.9 ± 1.0, P = .70, 96% power to detect difference of 1.0), with similar results after adjusting for age, sex, body mass index, and tonsil status. Neither tongue base nor epiglottic obstruction was associated with apnea index.

CONCLUSION

The number of subsites with complete obstruction on DISE was not associated with polysomnographic, subjective sleepiness, and quality-of-life measures. Tongue base and epiglottic obstruction were not associated with apnea index. Larger detailed analyses are needed to determine the importance of each site and degree of obstruction seen on DISE.