Radiation exposure alters airway deformability and bony structure displacement during laryngoscopy

BACKGROUND: Prior therapeutic radiation exposure in the setting of head and neck malignancies is associated with difficult airway instrumentation. We sought to characterize the anatomic changes that produce this phenotype. STUDY DESIGN: Retrospective review. METHODS: Five individuals with prior radiation therapy to the upper aerodigestive tract (previously irradiated) and 10 with no prior history of therapeutic radiation exposure (nonirradiated) were enrolled. Computed tomography images obtained before and during laryngoscope insertion (“uninstrumented” and “instrumented”, respectively) were used to reconstruct three‐dimensional representations of the pharyngeal airway, hyoid, and mandible. RESULTS: In the instrumented state, pharyngeal airway volumes were significantly greater in nonirradiated subjects relative to previously irradiated subjects (P = .01), and overall translation of both the hyoid and mandible was also greater in nonirradiated subjects (P = .01 and .04, respectively). CONCLUSION: Individuals with prior therapeutic radiation exposure to the upper aerodigestive tract differ from nonirradiated subjects with respect to airway deformation and bony structure translation during laryngoscopy. LEVEL OF EVIDENCE: 4