Long-Range Optical Coherence Tomography of the Neonatal Upper Airway for Early Diagnosis of Intubation-related Subglottic Injury.

Abstract

Subglottic edema and acquired subglottic stenosis are potentially airway-compromising sequelae in neonates following endotracheal intubation. At present, no imaging modality is capable of in vivo diagnosis of subepithelial airway wall pathology as signs of intubation-related injury. To use Fourier domain long-range optical coherence tomography (LR-OCT) to acquire micrometer-resolution images of the airway wall of intubated neonates in a neonatal intensive care unit setting and to analyze images for histopathology and airway wall thickness. LR-OCT of the neonatal laryngotracheal airway was performed a total of 94 times on 72 subjects (age, 1-175 d; total intubation, 1-104 d). LR-OCT images of the airway wall were analyzed in MATLAB. Medical records were reviewed retrospectively for extubation outcome. Backward stepwise regression analysis demonstrated a statistically significant association between log(duration of intubation) and both laryngeal (P < 0.001; multiple r(2) = 0.44) and subglottic (P < 0.001; multiple r(2) = 0.55) airway wall thickness. Subjects with positive histopathology on LR-OCT images had a higher likelihood of extubation failure (odds ratio, 5.9; P = 0.007). Longer intubation time was found to be significantly associated with extubation failure. LR-OCT allows for high-resolution evaluation and measurement of the airway wall in intubated neonates. Our data demonstrate a positive correlation between laryngeal and subglottic wall thickness and duration of intubation, suggestive of progressive soft tissue injury. LR-OCT may ultimately aid in the early diagnosis of postintubation subglottic injury and help reduce the incidences of failed extubation caused by subglottic edema or acquired subglottic stenosis in neonates. Clinical trial registered with www.clinicaltrials.gov (NCT 00544427).