Histopathological Changes in the Stenotic Part of the Airway in Post-Intubation Tracheal Stenosis.

Background: Post-intubation tracheal stenosis (PITS) is one of the most important early complications of intubation. In this study, a detailed examination of the histopathological changes of the trachea is presented. Materials and Methods: In this cross-sectional study, specimens of the stenotic region of the trachea in 25 patients with type III, type IV, and subglottic airway stenosis were evaluated using hematoxylin/eosin and Masson's trichrome staining. Also, the prevalence of microscopic changes in the different structures of the tracheal wall was assessed. Results: The mean age of the patients was 37.12±13.96 years, and the intubation duration was 12.6 ± 4.8 days. The length of stenosis part was 30.12± 6.4 mm. The location of stenosis in 19 patients was in the trachea, in five patients both the trachea and the subglottic area were affected, and in one patient only the subglottic area was restricted. In grade III, the epithelial layer was disorganized, and widespread cell destruction occurred. Also, the mucosal and submucosal layers were destroyed, and the accumulation of extracellular matrix and collagen fibers was clear, but the hyaline cartilage of the trachea was still intact and non-pathological. In Grade IV lesions, the tracheal tissue was extensively damaged, with complete destruction of the epithelial layers, lamina propria, mucosa, submucosa, seromucous glands, and tracheal cartilage. The extracellular matrix and collagen fibers were also extensively disrupted and replaced by fibrotic tissue. Conclusion: Tissue destruction in tracheal stenosis sometimes progresses to the depth of the cartilage layer and is irreversible. Thus, in many cases, anastomotic resection surgery is the only treatment.