Laryngotracheal stenosis: Mechanistic review

Abstract

Background: The purpose of this review article is to summarize the existing literature surrounding wound healing mechanisms in laryngotracheal stenosis.

Methods: A review of general wound healing pathophysiology, followed by a focused review of iatrogenic laryngotracheal stenosis (iLTS) and idiopathic subglottic stenosis (iSGS) as conditions of aberrant wound healing.

Results: iLTS is the scarring of the laryngotracheal complex, coming secondary to injury from prolonged intubation. iSGS is a chronic fibroinflammatory scarring and narrowing of the subglottic airway in the absence of any obvious preceding injury or trauma. They are both thought to result from a prolonged and dysregulated wound healing response that promotes the deposition of pathologic scar in the airway.

Conclusions: Understanding the mechanisms that underlie wound healing will help identify and intervene on the process early in its development and discover future therapies that target individual wound healing mechanisms limiting the incidence of this recalcitrant disease process.

Keywords: LTS; airway; laryngotracheal stenosis; subglottic stenosis; wound healing.

FIGURE 1

The different types of upper airway stenosis: posterior glottic stenosis, subglottic stenosis, and tracheal stenosis [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 2

The physiology of wound healing. The four phases of wound healing: bleeding and hemostasis, inflammation, proliferation, and epithelialization [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 3

Wound healing in the airway demonstrated by the evolution of posterior glottic stenosis. (A) Normal view of vocal folds under direct laryngoscopy. (B) Hemostasis and inflammation under direct laryngoscopy. (C) Proliferation phase, acute laryngeal injury following extubation as seen under direct laryngoscopy. (D) Proliferation phase, evolving granulation in intubation injury in the posterior glottis as seen under flexible laryngoscopy. (E) Mature posterior glottic stenosis with dense scar formation between the vocal processes as seen under direct laryngoscopy [Color figure can be viewed at wileyonlinelibrary.com]