Glottic web

Glottic webs are focal narrowings of the airway due to the formation of a membranous connection at the level of the true vocal folds ¹.

Clinical presentation

Symptoms include exercise intolerance, dysphonia, hoarseness, stridor, respiratory distress and airway obstruction⁷.

Infants may also present with a weak or high-pitched cry, feeding difficulties, failure to thrive, apnea and cyanosis⁵.

Generally, anterior glottic webs make intubation difficult or impossible ⁸.

Pathology

Webs vary in size and thickness and usually involve the anterior glottis extending inferiorly ⁶.  

Etiology

Most commonly glottic webs are acquired and may occur at any age ².

Acquired lesions should be further investigated as causes include:

• trauma close to the anterior commissure by endotracheal intubation, surgery, laser therapy and radiotherapy ³

• inflammation, e.g. gastro-esophageal reflux disease ¹

• infection, e.g. Corynebacterium diphtheriae, Bacillus cereus ⁴

• autoimmune disease, e.g. Crohn disease, pemphigoid, and plasmacytosis infiltrates ⁴

Congenital glottic webs are uncommon and are thought to result from disrupted laryngeal embryogenesis, specifically the failure of epithelial layer resorption at the laryngotracheal groove⁵.

Associations

Congenital anterior glottic webs are associated with various syndromes, particularly 22q11.2 deletion syndrome and therefore require further investigations ⁵.

Acquired anterior glottic webs are associated with recurrent tracheobronchitis, recurrent pneumonia and vocal fold scarring ². Laryngeal framework stenosis are also associated and can be either supraglottic, glottic - due to thyroid cartilage constriction - or subglottic - due to cricoid cartilage deformity ⁹.

Radiographic features

Although CT and virtual endoscopy can provide useful information aiding diagnosis and extension, anterior glottic webs are best evaluated by awake flexible laryngoscopy and, if necessary, a direct laryngoscopy or bronchoscopy ¹⁰.

CT

CT may show a blunting of the normally sharp angle between the vocal folds and a reduction in the size of the glottic opening ⁸.

Treatment and prognosis

A wide variety of open and endoscopic surgical procedures have been proposed depending on symptom severity and the anatomical extension of the anterior glottic web ⁷.

Treatment aims to relieve airway obstruction and provide a functional voice. However, anterior glottic web tend to reform following treatment ¹.

Differential diagnosis

• laryngeal atresia ⁷

• granulomatosis with polyangiitis ⁹

• sarcoidosis

• amyloidosis