Morphology of trachea in benign human tracheal stenosis: a clinicopathological study of 20 patients undergoing surgery

Abstract

Prolonged tracheal intubation of patients often leads to tracheal stenosis (TS), which may require surgical removal of the narrowed portion of the airway. We studied 20 patients with TS who underwent surgical ablation of the stenotic portion of trachea. The morphology of the tracheal segments was characterized and compared with clinical data and with the prognosis for the disease. We found that TS was usually due to an increase in the width of the mucosa as a result of the fibrosis associated with the chronic inflammation. Plasma cells were the predominant leukocyte type seen in the inflammatory infiltrates of the surgically removed portions of narrowed trachea. In the majority of TS samples, the epithelial surface was intact and presented cilia; in contrast, cilia disappeared when the tracheal lumen was completely obliterated. Mucosal cells and glands were also well preserved in TS samples. The need to remove TS segments was often related to previous tracheal surgery, which was also associated with closing of the tracheal lumen and ossification of cartilage rings. We conclude that (a). chronic inflammation and fibrosis are responsible for the narrowing of trachea in TS patients, (b). metaplastic ossification of cartilage rings only occurs after complete obliteration of the tracheal lumen, and (c). loss of cilia and presence of metaplastic bone tissue are indicators of a poor prognosis for TS.