Approach Considerations
General trauma (Advanced Trauma Life Support [ATLS]) protocol is indicated for any individual who is severely injured. The airway must be secured, and other organ systems (eg, cardiac, pulmonology, vascular) must also be stabilized. Before any diagnostic study can be performed, life-threatening injuries, such as vascular injuries or internal bleeding, must be corrected.
Generally, in the setting of a laryngeal fracture, chest and cervical spine radiographs are obtained to exclude associated cervical injuries. Other, nonroutine studies that may be helpful are cervical arteriography and water-soluble contrast studies of the esophagus and pharynx.
Laryngeal fractures are usually suspected based on symptoms and physical findings, but direct visualization of the larynx is critical to define the extent and location of injury. Endoscopy is the mainstay for direct visualization of the larynx and its surrounding structures. Abnormalities such as edema, hematomas, tears, exposed cartilage, vocal cord avulsion, vocal cord paralysis, and arytenoid dislocation can be assessed via endoscopy. Transnasal fiberoptic laryngoscopy is the procedure of choice in this setting because this procedure can assess the airway in the dynamic state and identify any abnormalities. Indirect laryngoscopy is usually avoided because of the gagging and coughing it elicits in a patient with an already compromised airway.
When the cause of laryngeal injury is not readily apparent, histological studies can help to determine the cause of injury and detect other macroscopic overlooked injuries. [27]
Imaging Studies
CT scanning
Computed tomography (CT) scanning is the imaging modality of choice to assess laryngeal anatomy. [4, 5, 6] A clear understanding of the Schaefer classification of laryngeal injuries is required to prevent morbidity and mortality. This classification system is based on a combination of the CT and endoscopic findings, which dictate treatment modalities.
CT scanning can help to detect laryngeal fractures in a patient with no clinical signs or symptoms. In patients with minor injuries and minimal symptoms (eg, edema, ecchymosis, small hematomas), a CT scan is unlikely to provide new information that would alter treatment. Similarly, a patient with airway compromise and clinically obvious fractures requires aggressive surgical treatment regardless of CT findings.
Used judiciously, information gained from a CT scan will guide proper management of the patient's condition and prevent unnecessary surgical exploration; thus, the CT scan is a cost-effective means of assessing laryngeal anatomy. [4]
CT devices capable of spiral technique and subsecond scan times, specifically those that can reconstruct two-dimensional axial sections, two-dimensional coronal and sagittal images, and three-dimensional images, can provide optimal imaging results. [28] Interest in the use of three-dimensional CT images is currently growing. This innovative and highly useful tool can provide useful information when attempting to diagnose a laryngeal fracture. Because of the complexity of laryngeal anatomy, three-dimensional CT imaging is especially useful when conventional CT, magnetic resonance imaging (MRI), and fibroscopy are unable to reveal laryngeal trauma. [29]
A study by Becker et al supported the efficacy of two-dimensional multiplanar reformation (MPR) and three-dimensional volume rendering, using multidetector CT scanning, in the evaluation of laryngeal fractures. The study involved 38 patients with a total of 59 laryngeal fractures, including of the thyroid, cricoid, and arytenoid cartilages; in addition, nine patients had associated hyoid bone fractures, and eight cartilages had arytenoid luxation. The investigators found two-dimensional MPR and three-dimensional volume rendering to be valuable in assessing laryngotracheal narrowing, arytenoid luxations, and fractures of the thyroid cartilage and hyoid bone, although they noted that three-dimensional volume rendering did not improve the evaluation of cricoid cartilage. [30]
A study by Schulze et al reported that in victims of hanging, the presence of the gas bubble sign on postmortem CT scanning is an accurate indicator of laryngeal fracture. In terms of identifying such fractures, according to the investigators, the gas bubble sign is 83% accurate, with a sensitivity and specificity of 79.2% and 90.9%, respectively, a positive predictive value of 95%, and a negative predictive value of 34.5%. [31]
MRI
Magnetic resonance imaging (MRI) has not gained acceptance as an evaluative tool for laryngeal fractures or trauma because of the length of time required to complete the scan and the increased physical demands placed on the patient (eg, holding breath for a long period). [32] In addition, MRI is not helpful for imaging skeletal structures.
Diagnostic Procedures
See the list below:
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The procedures below are used to evaluate patients with suspected laryngeal trauma.
Fiberoptic nasopharyngoscopy: This procedure is performed in a conscious patient, with topical anesthesia. The goal of the procedure is to evaluate vocal cord function and to perform a preliminary assessment of the extent of trauma.
Direct laryngoscopy: This procedure provides a detailed visual examination of the larynx. Instrumentation such as the Dedo or Pilling laryngoscope provides excellent visualization; however, complete examination of the anterior commissure may require special instrumentation.
Bronchoscopy: This procedure may be performed with either a flexible or rigid bronchoscope, depending on the experience of the operator. Examination allows observation of the subglottic larynx and supporting structures.
Esophagoscopy: This procedure allows visualization of the esophageal mucosa for traumatic lacerations. It may be performed with either a flexible or rigid esophagoscope, depending on the experience of the operator. Traumatic injury is common in the retrolaryngeal esophagus; therefore, close evaluation is required.
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Thyroid fracture.
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Hematoma of the false vocal fold.
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Stent placement.
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Posterior view of the laryngeal cartilages and ligaments.
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Sagittal view of the laryngeal cartilages and ligaments.
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Management protocol for laryngeal trauma.
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Fractured thyroid cartilage closed with wires.
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Laceration repair.
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Various methods for laryngeal cartilage stabilization.
Tables
Group |
Symptoms |
Signs |
Management |
Group 1 |
Minor airway symptoms |
Minor hematomas Small Lacerations No detectable fractures |
Observation Humidified air Head of bed elevation |
Group 2 |
Airway compromise |
Edema/hematoma Minor mucosal disruption No cartilage exposure |
Direct laryngoscopy Esophagoscopy |
Group 3 |
Airway compromise |
Massive edema Mucosal tears Exposed cartilage Vocal cord immobility |
Tracheostomy Direct laryngoscopy Esophagoscopy Exploration/repair No stent necessary |
Group 4 |
Airway compromise |
Massive edema Mucosal tears Exposed cartilage Vocal cord immobility |
Tracheostomy Direct laryngoscopy Esophagoscopy Exploration/repair Stent required |
