Difficult airways: a 3D printing study with virtual fibreoptic endoscopy

Head and neck cancer patients present unique airway challenges, and oropharyngeal, laryngeal, and hypopharyngeal tumours considerably distort and narrow the anatomy of the airway. We describe the use of 3D augmented reality software combined with 3D printed models to assess the anatomy of difficult airways and to assist in the formulation of the most optimal airway management strategy in such patients. The reported patients had computed tomograms (CT) of the neck prior to their anaesthetic and surgical management. DICOM files of the respective scans were imported to 3D rendering software (OsiriX, Pixmeo). We constructed volume rendered models for initial assessment of the airway then generated serial surface rendered models to create a virtual endoscopic path of the airway to simulate the fibreoptic approach. To further facilitate the study of difficult airways we have subsequently printed 3D models of those that were most difficult using rapid prototyping. Head and neck tumours significantly distort the airway. Thorough study of the relevant anatomy prior to airway management for operating reasons enhances communication between the surgeon and anaesthetist, and aids selection of the most appropriate intubation approach. In conclusion, this paper highlights a useful and novel pre-assessment strategy that allows a virtual, visual, 3-dimensional assessment of the airway anatomy combined with 3D modelling and 3D printing. This enables the airway specialist, anaesthetist, and head and neck surgeon to anticipate any critical steps and adjust the plan accordingly.