Tracheal Stenosis After Intubation

Tracheal stenosis after intubation is fixed narrowing of the trachea at the site of the cuff or the tracheostomy stoma, caused by pressure necrosis and scarring.

Epidemiology. Clinically significant stenosis follows 1% to 2% of prolonged intubations and 0.6% to 21% of tracheostomies, with variation across series. Symptoms appear 2 to 12 weeks after extubation (occasionally years).

Types. Cuff stenosis (circumferential ring at cuff site), stomal stenosis (at tracheostomy opening), tip-of-tube stenosis (granuloma) and tracheomalacia (loss of cartilage support).

Risk factors. Intubation over 10 days, high cuff pressure (over 30 cmH2O), tube movement, infection, hypotension, steroids, diabetes, reflux, obesity and large tube.

Pathophysiology.

Cuff pressure exceeding mucosal capillary perfusion (about 25 to 30 mmHg) causes ischaemia, ulceration, chondritis and healing by contracture. Circumferential scar narrows the lumen.

Exertional dyspnoea, stridor, wheeze unresponsive to bronchodilators, cough, difficulty clearing secretions, recurrent chest infection, and respiratory failure with minor infection. Symptoms appear once the lumen is under about 8 mm (about 50% to 75% narrowed).

Red flags.

• Stridor at rest.
• Respiratory failure.
• Rapid deterioration after infection.

Flow volume loop (fixed obstruction), CT with 3D reconstruction, and bronchoscopy to measure the distance from the cords and carina, length (stenosis over 1 cm needs resection), degree of narrowing and cartilage integrity. Avoid forcing a bronchoscope through a critical stenosis.

Differential diagnosis.

• Asthma.
• Chronic obstructive pulmonary disease.
• Tracheal tumour.
• Tracheomalacia.
• Granulomatosis with polyangiitis.
• Vocal cord dysfunction.

Secure the airway first. In emergency obstruction, use rigid bronchoscopy to dilate or core out the stenosis, with jet ventilation or extracorporeal support if needed.

• Simple short web like stenosis: balloon dilation or radial incision with local steroid injection (triamcinolone 10 to 40 mg locally in one session, repeated after 4 to 8 weeks; maximum 80 mg each session).
• Complex or recurrent stenosis over 1 cm, or with cartilage loss: tracheal resection with primary anastomosis (up to 4 cm in adults), which has success rates over 90% in experienced centres.
• Stent (silicone) only for patients unfit for surgery, because of migration, granulation and infection.
• Omeprazole: 40 mg orally once daily; continue for 8 weeks or longer; maximum 80 mg daily; reduce in severe hepatic impairment.

Prevention. Cuff pressure 20 to 30 cmH2O (measured every 8 hours), early tracheostomy when long ventilation is expected, correct tube size, and avoid hypotension and infection.

Monitoring. Spirometry and bronchoscopy at 3 months, 6 months and annually after repair.

Referral and escalation. Urgent thoracic surgery or interventional bronchoscopy referral for stridor, rapid progression or failed extubation.

Special groups. Patients with long term tracheostomy and children need airway surveillance.