According to clinical experience, tracheostomy is often associated with complications, such as granulomas, tracheomalacia, and tracheostenosis. And tracheostenosis can be seen in the late stage of tracheostomy, which is due to: 1) the contact with the tip of the rigid intubation tubes or tracheotomy tube, 2) injury caused by high cuff pressure leads to an end of the infusion of capillaries in the tracheal mucosa leading to ischemia. Healing by fibrosis leads to tracheal stenosis. Besides, stoma is deprived of supports by tracheal cartilage may cause stoma stenosis. In addition, stoma retraction is one of the challenges that the anesthesiologist often confronts.
In patients who present with a difficult airway, the preanesthesia evaluation is crucial to anesthesia management and patients' outcomes. There are various methods for evaluating difficult airways, including the Mallampati classification, interincisor distance, thyromental distance, and range of motion of the head and neck. These methods, however, were not suitable for this patient as they apply to routine intubation with a laryngoscopic view.
Imaging techniques such as CT and plain radiography are important aids for visualizing anatomy and pathology. In the present case, the 3D model was particularly important for aiding procedure planning and choosing the proper cannula location and size. We shortened the intubation time, increased intubation success rate, and avoided injuries caused by repeated intubation.
We used, for the first time, the 3D printout technique in a patient with laryngeal carcinoma who had undergone previous tracheotomy to present a new method of evaluating the difficult airway. The benefits of evaluating the airway with 3D models include the following: (1) 3D models are easy to interpret by the anesthesiologist and can better demonstrate tracheal anatomical structures and their relations with surrounding tissues. (2) 3D models enhance the anesthesiologist's understanding of the morphology, which may have been significantly altered by the underlying pathology. It could also help facilitate communication with team members to create a better preanesthesia plan. (3) 3D models with direct vision could enable the anesthesiologist to assess risk factors, adjust the plan, and provide manual accuracy. Accordingly, it would help shorten the intubation time and reduce injuries in patients. (4) Subsequent benefits may include medical education for interns and better understanding for patients.
The 3D printout technique also has limitations. It does not recognize color variations in the tracheal mucosa and thus cannot distinguish inflammation of the airway wall. Under these circumstances, visual techniques such as fiberoptic bronchoscopy can be helpful as a complement to the 3D printout technique.
BMC Anesthesiol. 2016;16(6) © 2016 BioMed Central, Ltd.