Subglottic stenosis after endolaryngeal intubation in infants and children: result of wound healing processes.

Objective: To study the histopathology of subglottic stenosis in children of different ages after treatment during different periods of time, with or without laser application. Partial resection of the anterior cricoid with adhering stenotic subglottic area in the live young patient provides unique material for studying wound healing and scarring processes.

Methods: 25 specimens obtained from partial cricotracheal resection (PCTR) in children, were histologically processed and stained with Haematoxylin and Eosin, Resorcin and Fuchsin (for elastic fibers), and immunohistochemical staining (for the presence of macrophages).

Results: All specimens were found to have severe and sclerotic scarring with squamous metaplasia of the epithelium, loss of glands and elastic mantle fibers (tunica elastica), and dilation of the remaining glands with formation of cysts. Also, the cricoid cartilage was affected on the internal and external side, with irreversible loss of perichondrium on the inside and resorption by macrophages of cartilage on both sides. Detrimental effects of laser therapy were demonstrated in four cases. The normal intercellular matrix was completely destroyed and the number of chondrocytes in the cartilage structure diminished.

Conclusion: Wound healing after laryngeal injury is a process of intense restoration and reorganization of the various tissues involved. This process, however, does not guarantee complete repair. In the severe cases irreversible scarring has replaced normal tissues. There seems to be no direct relationship between the length of the post-lesional period, the age of the patient and the severity of the stenosis. When subglottic stenosis has developed and the majority of the tissues is replaced by dense fibrous tissue, PCTR is strongly indicated to achieve renewed patency of the airway.