Subglottic stenosis
Subglottic stenosis is a condition describing stenosis (narrowing) of the subglottic airway (region below the vocal cords). It can be congenital or acquired .
Epidemiology
Subglottic stenosis is the third most common congenital airway abnormal. The incidence of subglottic stenosis has decreased in recent decades after it was realized that endotracheal intubation (especially prolonged) greatly increases the risk of development .
Clinical presentation
The clinical features of subglottic stenosis are variable depending on the degree of severity. Mild subglottic stenosis may only present on exertion of with infection (causing swelling of tissues exacerbating stenosis). Clinical features include:
- asymptomatic
- stridor (usually biphasic)
- dyspnea
- hoarse voice
- severe respiratory distress
- cyanosis
Pathology
Subglottic stenosis is caused by a narrowing of the subglottic airways, which can be congenital or acquired.
Congenital subglottic stenosis is caused by defects at birth, which cause thickening of soft tissues and/or cartilage of the airway .
Acquired subglottic stenosis has multiple causes, but the most common is traumatic secondary to endotracheal intubation (often prolonged or incorrectly sized) . Intubation causes pressure on the walls of the subglottic airway, causes congestion and edema, ultimately leading to ulceration and necrosis . This is replaced by fibrous tissue that narrows the airway.
Other acquired causes include
- infection
- gastroesophageal reflux disease
- granulomatosis with polyangiitis
- extrinsic compression
Radiographic features
The best method of diagnosis is with direct visualization on bronchoscopy, however, imaging may aid in diagnosis and surgical planning. Plain radiographs, CT, and MRI of the neck may demonstrate narrowing of the trachea .
Treatment and prognosis
Treatment includes both medical and surgical therapy. Medical therapy includes the use of steroids to reduce inflammation and edema , and proton pump inhibitors if reflux is thought to contribute. Surgical therapy may include endoscopic or open repair, stenting, or long-term tracheostomy .
Differential diagnosis
- laryngomalacia
- infections (i.e. croup)
- vocal fold paralysis
- laryngospasm
- tumors