Describe laryngeal trauma and laryngotracheal stenosis.

Laryngeal Trauma

• Laryngeal trauma is uncommon but immediately life-threatening, and its early management determines both survival and the eventual voice and airway.
• The larynx is protected by the mandible above and the sternum below, so injury implies considerable force.
• Mechanisms — blunt trauma: road traffic accidents (the classical "dashboard" or steering-wheel injury with the neck extended), clothesline injuries from a wire or rope across the neck, assault and sport; penetrating injury from knives and gunshot; strangulation and hanging; iatrogenic injury from intubation and surgery; inhalation burns; and caustic ingestion
• Features — hoarseness or aphonia; stridor and dyspnoea; surgical emphysema.
• The airway may deteriorate suddenly and hours after the injury, as oedema and haematoma develop — so a patient with laryngeal trauma is admitted and observed even if initially comfortable. This is the point most often missed
• Assessment — airway, breathing, circulation and the cervical spine first; then flexible nasendoscopy to assess the mucosa, cord mobility and haematoma; and CT of the larynx in a stable patient.
• Where the airway IS threatened, the airway of choice is a tracheostomy under local anaesthesia
• Endotracheal intubation is hazardous in laryngeal trauma.

Laryngotracheal Stenosis

• Laryngotracheal stenosis is narrowing of the airway from scar, granulation or cartilage collapse
• The commonest cause BY far IS prolonged or traumatic intubation, with the subglottis the usual site.
• Other causes — tracheostomy (at the stoma or the cuff site); external trauma; burns and caustic injury; granulomatosis with polyangiitis.
• Presentation — biphasic stridor, exertional dyspnoea and a normal or near-normal voice (in subglottic disease.
• IT IS repeatedly misdiagnosed AS asthma and treated with inhalers for months — so an "asthmatic" who does not respond to bronchodilators, or who has a history of intubation, should have the airway examined
• A flow-volume loop shows flattening of both the inspiratory and expiratory limbs in a fixed extrathoracic obstruction.
• Assessment — endoscopy, which is definitive, defining the site, length, degree and maturity of the stenosis and the state of the cords; with CT and virtual bronchoscopy
• The cotton-MYER grading classifies subglottic stenosis by the percentage of luminal obstruction
• Also assess reflux, pulmonary function and any systemic disease, and send ANCA
• Management — endoscopic: radial laser incisions with balloon dilatation and topical or injected mitomycin C or steroid, which suits short (under 1 cm), thin, non-circumferential stenoses without cartilage loss; frequently needing repetition