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.

Analysis of Lateral Decubitus Position During Sleep in Patients With Obstructive Sleep Apnea Using WatchPAT Device

Background and Objectives: Measurement of sleep parameters in both supine and non-supine positions is important for the diagnosis of positional obstructive sleep apnea (OSA). However, the influence of right and left lateral decubitus positions (RLDP and LLDP, respectively) on sleep parameters is relatively unknown and has not been well investigated. This study was performed to verify the associations between sleep parameters and lateral decubitus sleep position.Methods: A retrospective study was performed on 38 patients who were diagnosed with OSA and underwent surgical interventions from January 2014 to December 2016. Preoperative sleep parameters were evaluated with WatchPAT, and patients who slept sufficiently in both RLDP and LLDP to accurately analyze sleep parameters were enrolled in the study. Basic clinical data including body mass index (BMI) and nasal endoscopic findings of patients were assessed.Results: The difference in peripheral arterial tonometry apnea-hypopnea index (pAHI) and PAT respiratory disturbance index (pRDI) between RLDP and LLDP showed no association with the side of deviated nasal septum. Patients with higher BMI showed higher pRDI in LLDP than RLDP (p=0.038). The difference in sleep position percentage between RLDP and LLDP was negatively correlated with the difference in pRDI (p=0.023).Conclusion: Higher BMI patients with OSA might benefit more from sleeping in RLDP than LLDP. Patients slept longer in the lateral decubitus position that produced lower pRDI. Not only supine and non-supine positions, but also RLDP and LLDP need to be evaluated in patients with OSA.

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

STUDY OBJECTIVES

(1) to investigate if DISE findings are predictive of surgical response for patients undergoing MMA for OSA; and (2) to investigate the predictive value of jaw thrust maneuver during DISE in terms of surgical response to MMA.

METHODS

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

RESULTS

Sixty-four OSA patients (50 males [78.1%]; mean ± SD age = 51.7 ± 9.5 years; mean ± SD AHI = 49.0 ± 20.8 events/hour) were included. Thirty-nine patients were responders, and twenty-five were nonresponders. Adjusting for baseline characteristics and surgical characteristics (e.g., age, baseline AHI, degree of maxillary advancement), patients with complete anteroposterior epiglottic collapse had 0.239 times lower odds for response to MMA (95% confidence interval, 0.059-0.979; P = 0.047). No significant relationship was found between complete concentric velum collapse and MMA response. There was no statistically significant association between effect of jaw thrust maneuver during DISE on upper airway patency and treatment outcome of MMA.

CONCLUSIONS

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

Natural sleep endoscopy in obstructive sleep apnea: A systematic review

This study's objective is to systematically review the literature on natural sleep endoscopy (NSE), including the set-up, different scoring systems, visualized collapse patterns during natural sleep, additional measurements, and comparison of upper airway collapse between NSE and drug-induced sleep endoscopy (DISE). A computerized search on Medline, Web of Science and the Cochrane library was conducted, obtaining 39 hits. Ten prospective studies were included in which NSE was performed in adults with obstructive sleep apnea (OSA). This study's findings suggest the soft palate to be the most frequent site of obstruction (58.8 %), followed by the tongue base (43.2 %), lateral walls (29.9 %), and epiglottis (22.4 %), which is in line with previous findings during DISE. Based on this literature review, the authors conclude that at this stage high quality, comparative research between DISE and NSE is missing. To adequately compare findings between OSA patients, endoscopic classification of upper airway collapse should be standardized. Non-invasive predictive tools to determine pharyngeal collapse are currently under investigation and may obviate the need for invasive endoscopy. This review highlights the contribution of NSE in validating such novel diagnostic methods and in studying upper airway mechanics in a research setting, yet larger and adequately powered studies are needed.

Standardized framework to report on the role of sleeping position in sleep apnea patients

PURPOSE

Sleep apnea is a multifactorial illness which can be differentiated in various physiological phenotypes as a result of both anatomical and non-anatomical contributors (e.g., low respiratory arousal threshold, high loop gain). In addition, the frequency and duration of apneas, in the majority of patients with OSA, are influenced by sleeping position. Differences in characteristics between non-positional patients (NPP) and positional patients (PP) suggest another crucial phenotype distinction, a clinical phenotype focusing on the role of sleeping position on sleep apnea. Since this clinical phenotype distinction has therapeutic implications, further research is necessary to better understand the pathophysiology behind this phenotypic trait and to improve management of PP. Therefore, we suggest a standardized framework that emphasizes the role of sleeping position when reporting clinical and research data on sleep apnea.

METHODS

We identified 5 key topics whereby a standardized framework to report on the role of sleeping position would be of added value: (1) sleep study data, (2) anatomical, morphological and physiological factors, (3) drug-induced sleep endoscopy (DISE) findings, (4) sleep apnea management, and (5) effectiveness versus efficacy of positional therapy in sleep apnea management. We performed a literature search to identify evidence to describe and support the rationale behind these 5 main recommendations.

RESULTS

In this paper, we present the rationale behind this construct and present specific recommendations such as reporting sleep study indices (disease severity) and sleep time spent in various sleeping positions. The same is suggested for DISE findings and effect of treatment. Sleep study indices (disease severity), anatomical, morphological, and physiological factors in sleep apnea patients should be reported separately for PP and NPP.

CONCLUSION

Applying these suggestions in future research will improve patient care, assist in better understanding of this dominant phenotype, and will enhance accurate comparisons across studies and future investigations.

Role of drug-induced sleep endoscopy in evaluation of positional vs non-positional OSA

Background

The study aimed to evaluate the anatomical differences between positional and non-positional OSA, and to identify the potential predictors for distinguishing between these two types of OSA.

Methods

A cross-sectional study of 230 consecutive patients with OSA undergoing DISE (Drug-induced Sleep Endoscopy) was carried out at a tertiary academic medical center. The factors correlating with positional and non-positional OSA were analyzed, including clinical characteristics, polysomnography data, and DISE findings.

Results

Univariate analysis revealed that non-positional dependency was correlated with a higher BMI (p < 0.001), neck circumference (p < 0.001), modified Mallampati score (p = 0.003), AHI (p < 0.001), degree of velum concentric collapse (p = 0.004), degree of oropharyngeal lateral wall collapse (p < 0.001), and degree of tongue base anteroposterior collapse (p = 0.004). Multivariate analysis revealed that oropharyngeal lateral wall collapse (OR = 1.90, p = 0.027) was the only anatomical factor significantly predicted non-positional dependency in OSA patients. AHI (OR = 1.04, p < 0.001), although significant, made only a marginal contribution to the prediction of non-positional dependency.

Conclusions

Oropharyngeal lateral wall collapse was identified as the only anatomical predictor for non-positional dependency in OSA patients. Therefore, further treatment modalities should address the distinct anatomical trait between positional and non-positional OSA.

Graphical abstract

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.

Effect of back-up head-elevated position during drug-induced sleep endoscopy in obstructive sleep apnea patients

PURPOSE

This study aimed to evaluate the difference of upper airway collapse between the back-up head-elevated position (a 45° upward inclination) and supine position to better elucidate the role of back-up head-elevated position in reductions of obstructive sleep apnea (OSA) severity.

METHODS

From August 2016 to May 2019, 198 patients aged between 18 and 70 years were recruited in this study prospectively. Drug-induced sleep endoscopy (DISE) findings were recorded with the patients first placed in the supine position then into the back-up head-elevated position with a 45° upward inclination.

RESULTS

From the supine to back-up head-elevated position, a significant decrease in the severity of collapse was observed in velum anteroposterior collapse and velum concentric collapse (p < 0.001 and p < 0.001, respectively), which was more predominant in patients with mild OSA than in patients with moderate to severe OSA. On the other hand, there was no significant improvement of any other collapse at the level of oropharynx, tongue base, or epiglottis when the position was shifted from the supine into back-up head-elevated position.

CONCLUSIONS

The back-up head-elevated position with a 45° upward inclination improved upper airway obstruction during DISE in velum anteroposterior collapse and velum concentric collapse. The proportion of patients with amelioration of upper airway collapse was much higher in patients with mild OSA than in patients with moderate to severe OSA. The back-up head-elevated position may be a reasonable alternative to traditional positional therapy for certain subgroups of patients with OSA.

Drug-Induced Sleep Endoscopy in Children With Positional Obstructive Sleep Apnea

OBJECTIVE

Positional obstructive sleep apnea (POSA)-defined as obstructive sleep apnea twice as severe supine than nonsupine-may offer clues to the underlying pattern of upper airway collapse in children. We compared drug-induced sleep endoscopy (DISE) findings in children with and without POSA. We hypothesized that children with POSA would have significantly higher obstruction at the gravity-dependent palate and tongue base but not at the adenoid, lateral wall, or supraglottis.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary pediatric hospital.

SUBJECTS AND METHODS

We included children aged 1 to 12 years with obstructive sleep apnea diagnosed by polysomnography who underwent DISE from July 2014 to February 2019. Scores were dichotomized as ≥50% obstruction (Chan-Parikh 2 or 3) vs <50% obstruction (Chan-Parikh 0 or 1).

RESULTS

Of 99 children included, 32 (32%) had POSA and 67 (68%) did not. Children with POSA did not differ from children without POSA in age, overall apnea-hypopnea index, sex, race, syndromic diagnoses, obesity, or history of adenotonsillectomy. In logistic regression models, odds of ≥50% obstruction were significantly higher at the tongue base (odds ratio, 2.77; 95% CI, 1.04-7.39) after adjustment for age, sex, obesity, previous adenotonsillectomy, and syndrome. No difference was noted at the adenoid, velum, lateral wall, or supraglottis.

CONCLUSION

POSA was associated with higher odds of obstruction on DISE at the tongue base but not at other levels.

Drug-Induced Sleep Endoscopy Findings in Supine vs Nonsupine Body Positions in Positional and Nonpositional Obstructive Sleep Apnea

Importance

The anatomic mechanisms underlying positional vs nonpositional obstructive sleep apnea (OSA) are poorly understood and may inform treatment decisions.

Objective

To examine drug-induced sleep endoscopy (DISE) findings in the supine vs nonsupine body positions in positional and nonpositional obstructive sleep apnea.

Design, Setting, and Participants

A cross-sectional study of 65 consecutive eligible adults with OSA undergoing DISE without marked tonsillar hypertrophy, including 39 with positional OSA (POSA) and 26 with nonpositional OSA (N-POSA) was conducted in a sleep surgery practice at a tertiary academic medical center.

Exposures

Drug-induced sleep endoscopy performed in the supine vs nonsupine body position.

Main Outcomes and Measures

Drug-induced sleep endoscopy findings were scored separately for the supine and lateral body positions using the VOTE classification (velum, oroparyngeal lateral walls, tongue, epiglotis) and with identification of a single primary structure contributing to airway obstruction. Velum-related obstruction was separated into anteroposterior and lateral components.

Results

The 65 study participants had a mean (SD) age of 52.4 (11.7) years, and 55 (84.6) were men. Mean (SD) body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) was 27.2 (3.1), with only 9 (14%) of 65 participants having a BMI greater than 30. The supine body position was associated with greater odds of anteroposterior velum- (odds ratio [OR], 7.28; 95% CI, 3.53-15.01), tongue- (OR, 29.4; 95% CI, 12.1-71.5), and epiglottis-related (OR, 11.0; 95% CI, 1.3-92.7) obstruction in the entire cohort, with similar findings in the POSA and N-POSA subgroups. The supine body position was associated with a lower odds of oropharyngeal lateral wall-related (OR, 0.22; 95% CI, 0.07-0.70) obstruction in the N-POSA subgroup, whereas there was no increase in the overall sample or the POSA subgroup. The oropharyngeal lateral walls were a common primary structure causing obstruction, especially in the lateral body position.

Conclusions and Relevance

In a study population of primarily nonobese adults, DISE findings differed based on body position, generally corresponding to gravitational factors. Treatments that address velum- and tongue-related obstruction successfully may be more effective in the POSA population.

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

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

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.

The effect of body position on airway patency in obstructive sleep apnea: CT imaging analysis

PURPOSE

Positional change during sleep influences upper airway patency. However, few studies have used imaging techniques to demonstrate the change. This study aims to determine the effect of positional change on the upper airway space.

METHODS

A total of 118 subjects with sleep breathing disorders were analyzed. Participants underwent upper airway CT scans in the supine and lateral decubitus positions (right and left). They were divided into non-obstructive sleep apnea (n = 28) and obstructive sleep apnea (n = 90) groups. We measured the minimal cross-sectional area of the retropalatal/retroglossal spaces and compared the differences of those two spaces in the supine and lateral positions. CT was performed while patients were awake.

RESULTS

The minimal cross-sectional area in the OSA group was significantly smaller than non-OSA group in both supine (median[interquartile range], 8.3[0.0-25.1] vs 22.2[1.0-39.6]; P = 0.018) and lateral decubitus positions (5.2[0.0-16.9] vs 21.3[6.1-38.4]; P = 0.002). As the body position of OSA patients shifted from supine to lateral, the retroglossal space increased significantly (67.3[25.1-116.3] vs 93.3[43.4-160.1]; P < 0.001). However, there was no significant difference in the retropalatal space between the supine and lateral decubitus positions.

CONCLUSIONS

Positional change from the supine to lateral decubitus position expands the upper airway lumen, especially the retroglossal space. Positional OSA may be related to anatomical change of the upper airway lumen based on body position.

Drug-Induced Sleep Endoscopy in Treatment Options Selection

Drug-induced sleep endoscopy is a safe and practical technique to evaluate the dynamic upper airway collapse during sleep. We review drug-induced sleep endoscopy in adults, including its indications, technique, evaluation of upper airway collapse, and clinical application. Drug-induced sleep endoscopy is useful to improve treatment options selection for patients with obstructive sleep apnea, especially for those who are unable to accept or tolerate continuous positive airway pressure therapy. Owing to a lack of standardization for drug-induced sleep endoscopy, it is difficult to compare the published literature from different sleep centers across the world.

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.

Drug-induced sleep endoscopy: from obscure technique to diagnostic tool for assessment of obstructive sleep apnea for surgical interventions

PURPOSE OF REVIEW

Provide a practical update on drug-induced sleep endoscopy (DISE) for anesthesia providers, which can also serve as a reference for those preparing to establish a DISE program.

RECENT FINDINGS

New developments in surgical approaches to OSA and the growing global incidence of the condition have stimulated increased interest and demand for drug-induced sleep endoscopy. New techniques include transoral robotic surgery and hypoglossal nerve stimulation. Recent DISE literature has sought to address numerous debates including relevance of DISE findings to those during physiologic sleep and the most appropriate depth and type of sedation for DISE. Propofol and dexmedetomidine have supplanted midazolam as the drugs of choice for DISE. Techniques based on pharmacokinetic models of propofol are superior to empiric dosing with regard to risk of respiratory compromise and the reliability of dexmedetomidine to achieve adequate conditions for a complete DISE exam is questionable.

SUMMARY

The role of DISE in surgical evaluation and planning for treatment of OSA continues to develop. Numerous questions as to the optimal anesthetic approach remain unanswered. Multicenter studies that employ a standardized approach using EEG assessment, pharmacokinetic-pharmacodynamic modelling, and objectively defined clinical endpoints will be helpful. There may be benefit to undertaking DISE studies in non-OSA patients.

Upper Airway Areas, Volumes, and Linear Measurements Determined on Computed Tomography During Different Phases of Respiration Predict the Presence of Severe Obstructive Sleep Apnea

PURPOSE

The objective of this study was to analyze the potential of using low-dose volumetric computed tomography (CT) during different phases of respiration for identifying patients likely to have severe obstructive sleep apnea (OSA), defined as a respiratory disturbance index (RDI) higher than 30.

PATIENTS AND METHODS

A prospective study was undertaken at the Ramathibodi Hospital (Bangkok, Thailand). Patients with diagnosed OSA (N = 82) were recruited and separated into group 1 (RDI, ≤30; n = 36) and group 2 (RDI, >30; n = 46). The 2 groups were scanned by low-dose volumetric CT while they were 1) breathing quietly, 2) at the end of inspiration, and 3) at the end of expiration. Values for CT variables were obtained from linear measurements on lateral scout images during quiet breathing and from the upper airway area and volume measurements were obtained on axial cross-sections during different phases of respiration. All CT variables were compared between study groups. A logistic regression model was constructed to calculate a patient's likelihood of having an RDI higher than 30 and the predictive value of each variable and of the final model.

RESULTS

The minimum cross-sectional area (MCA) measured at the end of inspiration (cutoff point, ≤0.33 cm²) was the most predictive variable for the identification of patients likely to have an RDI higher than 30 (adjusted odds ratio [OR] = 5.50; 95% confidence interval [CI], 1.76-17.20; sensitivity, 74%; specificity, 72%,), followed by the MCA measured at the end of expiration (cutoff point, ≤0.21 cm²; adjusted OR = 3.28; 95% CI, 1.05-10.24; sensitivity, 70%; specificity, 68%).

CONCLUSION

CT scanning at the ends of inspiration and expiration helped identify patients with an RDI higher than 30 based on measurement of the MCA. Low-dose volumetric CT can be a useful tool to help the clinician rapidly identify patients with severe OSA and decide on the urgency to obtain a full-night polysomnographic study and to start treatment.

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.

Interventional Drug-Induced Sleep Endoscopy: A Novel Technique to Guide Surgical Planning for Obstructive Sleep Apnea

STUDY OBJECTIVE

One of the challenges of surgery for obstructive sleep apnea (OSA) is identifying the correct surgical site for each patient. The objective of this study was to use drug-induced sleep endoscopy (DISE) and nasopharyngeal tube (NPT) placement to determine the effect of eliminating palatal collapse on the obstruction seen on other segments of the upper airway.

METHODS

Forty-one OSA patients were enrolled in this prospective study. All patients had a polysomnogram followed by DISE. DISE findings were recorded and compared with and without placement of a NPT. Obstruction was graded with a scale that incorporates location, severity, and interval of obstruction.

RESULTS

Most patients (83%) demonstrated multilevel obstruction on initial DISE. With the nasopharyngeal airway in place, many patients with multilevel obstruction had at least a partial improvement (74%) and some a complete resolution (35%) of collapse (p < 0.05). Reduction in collapse was observed at the lateral walls (86%), epiglottis (55%), and tongue base (50%). NPT placement did not significantly alter upper airway morphology of patients with incomplete palatal obstruction or mild OSA.

CONCLUSIONS

To our knowledge, this is the first study to evaluate the effect of soft palatal stenting on downstream pharyngeal obstruction during DISE. Our study provides evidence that reducing soft palatal collapse can reduce negative pharyngeal pressure and thereby alleviate other sites of upper airway obstruction. Taken together, these findings provide a means to identify appropriate candidates for isolated palatal surgery and better direct a minimally invasive approach to the surgical management of OSA.

[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.

Surgical Management of Obstructive Sleep Apnea

Surgical management of snoring and obstructive sleep apnea is indicated when a surgically correctable abnormality is believed to be the source of the problem. Many patients opt for surgical treatment after noninvasive forms of treatment have been proven ineffective or difficult to tolerate. With increasing frequency, functional rhinoplasty, septoplasty, turbinoplasty, palatal surgery, and orthognathic surgery are being used in the management of snoring and obstructive sleep apnea. Plastic surgeons' experience with aesthetic nasal surgery, nasal reconstruction, palatal surgery, and craniofacial surgery puts them at the forefront of performing surgery for snoring and sleep apnea. The role of functional septorhinoplasty, turbinoplasty, palatal surgery, genioglossal advancement, and orthognathic surgery is indispensable in the surgical management of obstructive sleep apnea. Multidisciplinary management of these patients is critical, and plastic surgeons are encouraged to work collaboratively with sleep medicine clinicians and centers.