Upper Airway Soft Tissue CT Measurements and Collapsibility During DISE

Monday, October 2, 2023

8:18 AM - 8:24 AM East Coast USA Time

Location: 103A

Presenting Author(s)

Eric Thuler, MD, PhD, MBA

Postdoctoral Researcher
University of Pennsylvania
Philadelphia, PA, United States

Co-Author(s)

AW

Andrew Wiemken, MPH

University of Pennsylvania
Philadelphia, PA, USA
ES

Everett G. Seay, BS, RPSGT

Research Program Manager
Division of Sleep Surgery, Penn Otorhinolaryngology
Philadelphia, PA, United States
Brendan T. Keenan, MS

Co-Director
Biostatistics Core, Division of Sleep Medicine
Philadelphia, PA, USA
RS

Richard J. Schwab, MD, DABSM

Medical Director
University of Pennsylvania
Philadelphia, PA, United States
Raj C. Dedhia, MD, MSCR

Associate Professor of Otorhinolaryngology & Medicine
Division of Sleep Surgery, Penn Otorhinolaryngology
Philadelphia, PA, United States

Senior Author(s)

AS

Alan R. Schwartz, MD

Adjunct Professor; Part-time faculty
University of Pennsylvania
BALTIMORE, Maryland, United States

Disclosure(s):

Eric Thuler, MD, PhD, MBA: No relevant relationships to disclose.

Raj C. Dedhia, MD, MSCR: No relevant relationships to disclose.

Introduction: The influence of soft tissue hypertrophy on upper airway (UA) collapsibility remains debated for OSA. Titrating positive airway pressure (PAP) during drug-induced sleep endoscopy (DISE) can provide quantitative measures of UA collapsibility. Herein, we analyzed the relationship of measures of UA soft tissue volumes, specifically soft palate, pharyngeal lateral wall, and tongue, with metrics of UA collapsibility.

Methods: A cross-sectional analysis from a prospective cohort of patients undergoing DISE PAP titrations and CT imaging. The PAP titration protocol involved determining (1) the pressure at which inspiratory airflow first commenced (critical pressure, Pcrit), and (2) the pressure at which inspiratory flow limitation was abolished (pharyngeal opening pressure, PhOP). An airway-focused CT-validated protocol was applied to obtain UA soft tissue measures blinded to the clinical data. Spearman's linear and multiple regression tests were applied for statistical analysis before and after adjustments.

Results: Sixty-five subjects completed both DISE PAP and CT protocols (72.3% male, mean (SD) age 54.6 (14.4) years, BMI 30.1 (5) kg/m², and AHI 30.8 (23)). The soft palate volume (β=0 mmH2O/cm3; p=0.56 and β=0 mmH2O/cm3; p=0.99) and pharyngeal lateral wall (β=0.05 cmH2O/mm3; p=0.66 and β=0.01 cmH2O/mm3; p=0.94) were not associated with both Pcrit and PhOP, respectively. The tongue volume was associated with Pcrit (β=0.28 mmH2O/cm3; p=0.02) and trending association with PhOP (β=0.23 mmH2O/cm3; p=0.06).

Conclusions: Tongue volume suggested an association with increases in collapsibility during DISE, while soft palate and lateral pharyngeal wall volumes were not associated. Further incorporating larger sample sizes and skeletal dimensions may be required to elucidate the modulation of pharyngeal collapsibility by soft and bony structures.