Tracheal Stenosis (Narrowing of the Windpipe)

What is tracheal stenosis?

The trachea is a tube about 10 to 12 cm (4 to 5 inches) long, held open by C-shaped rings of cartilage, running from the voice box (larynx) to where it splits into the two main bronchi. When scar tissue, inflammation or a mass narrows it, airflow becomes turbulent and more effort is needed to breathe.

Because the body can cope with a lot of narrowing at rest, symptoms often appear only when the airway has narrowed by about half or more, and first during exertion. Narrowing just below the vocal cords is called subglottic stenosis.

Symptoms

• Shortness of breath on exertion, progressing to breathlessness at rest
• Stridor: a harsh, high-pitched noise, mainly when breathing in
• Wheezing that may be mistaken for asthma or COPD
• Cough and difficulty clearing mucus
• Frequent chest infections
• Voice changes if the narrowing is near the vocal cords

Symptoms usually develop gradually. Post-intubation stenosis typically appears weeks to a few months after the breathing tube is removed.

Causes

Tracheal stenosis vs asthma

Many people with tracheal stenosis are first treated for asthma. Clues that point to a fixed airway narrowing:

• Inhalers and steroids do not help
• The noise is mainly on breathing in (stridor) rather than out
• Symptoms began after an ICU stay or intubation
• Breathing tests show a flattened flow-volume loop, a pattern typical of a fixed upper airway obstruction

Diagnosis

• Pulmonary function tests with flow-volume loops can suggest an upper airway obstruction.
• CT scan of the neck and chest, sometimes with 3D reconstruction, shows the length and degree of narrowing and any outside compression.
• Bronchoscopy: a flexible camera passed through the nose or mouth directly shows the narrowing. It is the key test and can also allow treatment.
• Laryngoscopy checks the vocal cords.
• Blood tests for autoimmune causes, such as ANCA for granulomatosis with polyangiitis.
• Biopsy if a tumor is suspected.

Treatment

Treatment depends on the cause, length and severity of the narrowing and your general health. It is usually done at a center with interventional pulmonology, ENT and thoracic surgery expertise.

Endoscopic treatments (through a bronchoscope)

• Balloon dilation: a balloon gently stretches the narrowed segment. Often combined with laser cuts in the scar and steroid injections. Relief is often good but may need repeating, sometimes every few months.
• Laser or cryotherapy: removes scar tissue or tumor.
• Airway stents: silicone or metal tubes that hold the airway open, mainly used when surgery is not possible. They can cause mucus buildup, migration and granulation tissue.

Surgery

• Tracheal resection and reconstruction: the narrowed segment is removed and the ends sewn together. It offers the best chance of a permanent cure for suitable patients, with high success rates at experienced centers.
• Cricotracheal resection: for subglottic stenosis close to the vocal cords.
• Tracheostomy: a breathing tube in the neck below the narrowing, used in emergencies or when other options are not possible.

Treating the cause

Immunosuppressive medicines for autoimmune disease, cancer treatment for tumors, and treating reflux, which may contribute to idiopathic subglottic stenosis.

Outlook

Many people achieve good breathing with endoscopic treatment, though repeat procedures are common. Tracheal resection cures most suitable patients. Idiopathic subglottic stenosis tends to recur after dilation, so patients and doctors weigh repeated dilations against more definitive surgery.

Prevention

In hospitals, using the right tube size, keeping cuff pressures low, limiting the duration of intubation and timing tracheostomy appropriately reduce the risk of post-intubation stenosis.

Frequently asked questions

What are the symptoms of tracheal stenosis?

Common symptoms are shortness of breath on exertion, a harsh high-pitched sound when breathing in (stridor), wheezing, cough, trouble clearing mucus and repeated chest infections. Symptoms often worsen gradually and may be mistaken for asthma, particularly when inhalers do not help.

What causes tracheal stenosis?

The most common cause is scarring after a breathing tube or tracheostomy. Other causes include autoimmune diseases such as granulomatosis with polyangiitis, tumors, neck injury, burns, infections and inhaled toxins. In idiopathic subglottic stenosis, which mainly affects women, no cause is found.

Can tracheal stenosis come back after treatment?

Yes. Narrowing often returns after balloon dilation or laser treatment, sometimes within months, and repeat procedures are common. Surgical resection of the narrowed segment has the lowest recurrence rate and can be a permanent cure in suitable patients.

How long after intubation does tracheal stenosis develop?

Symptoms usually appear a few weeks to a few months after the breathing tube is removed, as scar tissue matures and contracts. Anyone who develops increasing breathlessness or noisy breathing after a stay in intensive care should mention their intubation to their doctor.

Is tracheal stenosis life-threatening?

It can be if the airway becomes very narrow, because a small amount of swelling or mucus can then block it. Severe breathlessness at rest, stridor or blue lips need emergency care. With diagnosis and treatment, most people have good control of their breathing.