Tracheal stenosis: windpipe narrowing explained

Stenosis means narrowing. A recent review in BMC Pulmonary Medicine describes tracheal stenosis as a pathological reduction in the diameter of the trachea, and says the primary criterion for diagnosis is a reduction in the cross-sectional area of the airway of more than 50%.

There are two broad groups. Congenital stenosis is present from birth and is mostly seen in children. Acquired stenosis develops later, most often from injury and scarring. The review also describes malignant narrowing caused by nearby or primary tumours, which is managed differently and is not the focus of this page.

Great Ormond Street Hospital explains that normally the cartilage rings give the windpipe its structure. When a child has tracheal stenosis, the rings are often complete circles, and more than two-thirds of the trachea is affected in the long segment type.

In children, GOSH says there are two main patterns. Most have noisy breathing called stridor. Others have sudden, severe breathing problems in which a child could stop breathing and turn blue, which can be life-threatening without immediate first aid. It may become apparent only after a chest infection causes breathing difficulty out of proportion to the infection.

In adults, the Ethiopian case series says symptoms develop gradually, usually presenting 1 to 6 weeks after extubation, with progressive breathlessness, stridor, cough, wheezing and recurrent pneumonia. The recent review says symptoms vary with the severity and the person's cardiorespiratory reserve.

A persistent noise on breathing in, especially after a breathing tube, should be looked at.

• Noisy breathing, especially a high-pitched sound on breathing in (stridor)

• Breathlessness that gets steadily worse

• Cough, wheeze or repeated chest infections

• In babies and children, difficulty feeding or breathing difficulty out of proportion to a cold

• Sudden severe breathing difficulty, which is an emergency

In adults, the recent review says prolonged intubation or tracheostomy is the commonest cause of benign stenosis. Others include tumours, inflammatory or infectious processes, and foreign bodies. The Ethiopian series says tracheal ischaemia from high-pressure cuffs on breathing tubes is the main mechanism, and that low-pressure cuffs have not removed the problem. It quotes reported prevalence after prolonged intubation of 0.6 to 21%.

In children, GOSH says tracheal stenosis is sometimes associated with other problems such as a heart defect, so doctors examine the child closely. GOSH also describes acquired narrowing in children most often due to injury, which can include a breathing tube used during intensive care.

The recent review also lists autoimmune and inflammatory causes.

The first step is history and examination, including reports of stridor at rest or with exercise. The recent review says lung function tests, such as spirometry, are mostly used in adults and can suggest a fixed upper airway obstruction, but correlate poorly with severity and cannot show exactly where the narrowing is.

CT shows the position and length of the narrowing, and is described as obligatory for more severe grades where there is no urgent need for a tracheostomy. The review calls bronchoscopy, passing a camera into the airway, the cornerstone of diagnosis. It lets the doctor measure the narrowing and sample tissue.

GOSH says in children the tests include bronchoscopy, a bronchogram with optical coherence tomography, a CT scan and an echocardiogram to check the heart and blood vessels.

Treatment depends on the cause, length and severity. GOSH says if a child has only one or two fixed rings or few problems, doctors may suggest watching and waiting. If treatment is needed, the affected rings can be removed and the ends joined, a tracheal resection. For long segment stenosis, a slide tracheoplasty may be needed, sometimes as an emergency operation. GOSH describes the operation as lasting about four hours under general anaesthetic with a heart-lung bypass machine.

GOSH says about a third of children need further procedures, such as widening the trachea with a balloon, or a stent if the trachea becomes floppy. After resection, scarring at the join can lead to narrowing that needs balloon dilatation at regular intervals for some time.

For adults, the Ethiopian series says definitive management remains surgical resection with end-to-end joining, and that bronchoscopic dilatation can be an initial or definitive option for those unfit for surgery or with simple, short narrowing. In that series surgery gave a better outcome than dilatation (89.1% against 75.0%), which should be read as a single-centre result from a different health system.

Call 999 for severe difficulty breathing, blue lips or face, or a child who stops breathing. GOSH recommends that parents learn basic life support, and notes free classes are available from voluntary organisations.

After surgery, GOSH advises calling the team if a child starts to make a lot of noise breathing, seems to make more effort to breathe, is not feeding well, or is generally unwell. For adults with new stridor after a breathing tube, seek same-day medical assessment through NHS 111 or the emergency department.

GOSH says that after slide tracheoplasty breathing problems are likely to be less severe, the first year can be the most demanding for families, and follow-up starts weekly and reduces over time. It reports that children should be able to have a near normal life, and that most who are smaller than their peers catch up in time.

In the NHS, children are referred to specialist airway units, and adults to ENT or thoracic surgical teams with airway expertise. Private surgeons also offer airway endoscopy and surgery. Ask how often the team treats this condition and what follow-up bronchoscopy is planned.