Predicting critical closing pressure in children with obstructive sleep apnea using fluid-structure interaction.

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Sleep Medicine

Background:

• Surgical treatment for obstructive sleep apnea (OSA) in children necessitates understanding upper airway dynamics, specifically critical closing pressure (Pcrit), which indicates airway collapsibility.
• Accurate Pcrit estimation is crucial for effective surgical interventions in pediatric OSA.

Purpose of the Study:

• To apply a patient-specific fluid-structure interaction (FSI) computational model to estimate Pcrit in children with Down syndrome.
• To evaluate the agreement between measured and FSI-estimated Pcrit and its association with OSA severity (AHI).

Main Methods:

• A flow-structure interaction (FSI) computational model was developed using patient-specific upper airway models derived from magnetic resonance imaging (MRI) scans.
• Polysomnography and sedated sleep MRI were performed on 41 participants.
• Bland-Altman plots and regression models were used to assess agreement and associations between measured/estimated Pcrit and AHI.

Main Results:

• The FSI model demonstrated good agreement with measured Pcrit, with a fixed bias of -1.31 and nonsignificant proportional bias for passive Pcrit.
• A regression model incorporating AHI, gender, and neck circumference explained significant variation (R² = 0.61) in estimated Pcrit.
• High overlap (77.4-78.6%) was observed between low airway stiffness regions and dynamic MRI-identified collapse areas.

Conclusions:

• The FSI model provides a valid, noninvasive method for estimating Pcrit in pediatric OSA patients.
• The model's accuracy in estimating Pcrit and its significant association with AHI support its utility in assessing OSA severity.
• This approach can inform surgical treatment strategies by providing objective measures of upper airway collapsibility.