Development of a Novel Diagnostic Modality for Upper Airway Obstruction in Neonates.

OBJECTIVES/HYPOTHESIS: To develop and validate a novel diagnostic modality to quantify upper airway obstruction (UAO) in patients with Robin Sequence.

METHODS

Clinical and imaging data were retrospectively collected for 10 patients with Robin Sequence (RS) who underwent dynamic upper airway computed tomography (4D-CT). 4D-CT data were analyzed using computational fluid dynamics (CFD) methodologies. For each subject, the following CFD variables were calculated: airway resistance, peak velocity, energy dissipation, and minimal cross-sectional area. Clinical data, including method of respiratory support, level of respiratory support, blood CO2 level, and polysomnogram results, were also examined.

RESULTS

The integration of 4D-CT with CFD yielded an anatomically precise representation of airflow features at inspiration and expiration relative to the more conventional measures of cross-sectional area. Comparing the most severe to the least severe patient, 32x, 24×, and 5× greater values for resistance, viscous dissipation, and peak velocity at peak inspiration were observed. Clinical severity appeared related to the strength of jet formation and large velocity gradients downstream of the obstructions.

CONCLUSIONS

4D-CT/CFD acquisition and analyses in RS patients appear to have beneficial descriptive utility at identifying critical anatomical loci and flow restrictions on a patient-by-patient basis. With further studies, this diagnostic approach for neonates and young children with UAO has the potential to inform severity assessment and guide surgical decision-making. Additional data and expanded metrics will be helpful to refine and extend these observations.