DISE: Phenotyping Obstruction Patterns

Study Overview
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Brief Summary
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Drug-induced sleep endoscopy (DISE) represents an opportunity to evaluate the upper airway in sleep-like conditions. In its current clinical form, however, DISE does not routinely determine the functional impact of anatomic and neuromuscular factors on airflow obstruction. The investigators will apply nasal pressure (CPAP) during DISE to generate pressure-flow and pressure-area relationships, deriving functional determinants of upper airway obstruction during sleep. In addition, they will use objective anatomic measurements from computerized tomography (CT) and submental ultrasound. The findings will allow the investigators to streamline the upper airway exam during DISE, and will further the goal of developing personalized solutions that address specific pathogenic mechanisms of pharyngeal collapse and airflow obstruction during sleep. The investigators will use the physiologic and anatomic features derived from DISE and imaging to determine which are predictive of success to standard-of-care surgical interventions (e.g. skeletal, soft tissue, neurostimulation) .

Detailed Description
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Obstructive sleep apnea (OSA) is characterized by recurrent upper airway obstruction due to inadequate muscle tone during sleep leading to nocturnal hypercapnia, repeated oxyhemoglobin desaturations and arousals. Continuous positive airway pressure (CPAP) is the therapeutic mainstay for OSA, but adherence remains poor. Currently, there exist 3 classes of surgical therapy for OSA, each addressing a specific pathologic structure: skeletal surgery (target: jaw bones), neurostimulation (target: tongue), and soft tissue (target: soft palate). Unfortunately, there is a critical knowledge gap in terms of accurately identifying a patient's underlying mechanism of obstruction; as a result, the efficacy of surgical treatment is limited. Drug-induced sleep endoscopy (DISE) represents an opportunity to evaluate the upper airway in sleep-like conditions. In its current clinical form, however, DISE does not routinely determine the functional impact of anatomic and neuromuscular factors on airflow obstruction. In June 2020, the investigators implemented a pilot protocol (IRB # 833511) to utilize measures of airflow, pressure catheters, and ultrasound to enhance DISE exams. Over the course of 100 patients, they refined the research protocol to generate a safe, efficient, and comprehensive physiologic exam of the upper airway in the clinical setting (Dedhia et al, ORL, 2021, in press). Upper airway pressure-flow and pressure-area relationships will be characterized during a standard-of-care DISE by stepping through a range of nasal pressure (CPAP) levels to derive functional determinants of upper airway obstruction during sleep. The investigators' preliminary work in this area has shown patients requiring lower pressures to restore airflow experience improved outcomes with neurostimulation surgery. Their overall hypothesis is that upper airway pressure-flow/area relationships can be used to predict response to all 3 major classes of sleep surgery: skeletal, neurostimulation, and soft tissue. They will address this hypothesis by characterizing upper airway pressure-flow and pressure-area relationships while utilizing objective anatomic measurements from CT and ultrasound. These findings will allow investigators to streamline the upper airway exam during DISE, and will further the goal of developing personalized solutions that address specific pathogenic mechanisms of pharyngeal collapse and airflow obstruction during sleep.

Official Title
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Drug-Induced Sleep Endoscopy (DISE): Phenotyping Obstruction Patterns

Conditions
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Obstructive Sleep Apnea

Intervention / Treatment
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* Other: Pharyngeal Manometry
* Other: Submental Ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults (≥ 18yrs) willing and capable of providing informed consent. English-speaking & able to give Informed Consent. Referred or scheduled for clinically indicated DISE procedure. Seeking CPAP alternatives for treatment of sleep disordered breathing. Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Drug-Induced Sleep Endoscopy<br>Drug-Induced Sleep Endoscopy | Other: Pharyngeal Manometry<br>* Catheters will be passed into the nose and advanced to the pharynx to measure airway pressures during drug-induced sleep.<br>Other: Submental Ultrasound<br>* Ultrasound of airway soft tissues<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identify the pathogenic determinants of airway obstruction at specific sites of pharyngeal collapse by characterizing upper airway pressure-flow/area relationships during DISE to predict responses to upper airway surgery | Change in pre-operative to post-operative AHI | Within 1 year of enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of anatomic measurements from computerized tomography (CT) scans to physiologic findings from DISE | Craniofacial measurements of bones and soft tissues from CT scans | Within 3 months of enrollment | 
| Complement videoendoscopic DISE findings with synchronous ultrasound imaging | Ultrasonic evaluation of dynamic tongue motion during DISE | Within 3 months of enrollment | 
| Compare positive airway pressure levels obtained from natural sleep to those during DISE | Therapeutic CPAP levels | Within 3 months of enrollment | 
| Examine outcomes associated with non-surgical treatments (e.g. oral appliance therapy) | Polysomnography metrics (e.g., apnea:hypopnea ratio), questionnaire data (ESS, ISI, FOSQ-10, NOSE, Snoring VAS, etc.) | Within 1 year of enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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drug-induced sleep endoscopy, snoring, sleep apnea