Methods: Fifty male adult Sprague Dawley rats (weighing mean 200 g to 300 g) were divided into five groups. An incision was performed between the fifth and sixth cartilage ring of the trachea in all groups under anesthesia and the incision was primarily repaired with a 6/0 monofilament absorbable suture. A single dose of mitomycin-C 0.5 mg was applied in the experimental animals appropriate with their assigned groups as topical, intraperitoneal injection, injection to the wound edges, and through inhalation. No mitomycin-C was administered in one group which was accepted as the control group. Rats were sacrificed four weeks after surgery and their tracheas were excised subsequently. Tracheal tissue samples were histopathologically evaluated in terms of epithelization, fibrosis, amount of fibroblasts, angiogenesis, and inflammatory response. Diameter and wall thickness of the tracheas were measured. Blood urea and creatinine levels were evaluated for nephrotoxicity, and the rats were immunohistochemically examined for glomerular pathology.

Results: Epithelization was statistically significantly decelerated (p<0.01), diameter of the trachea was statistically significantly larger (p<0.05), and wall thickness of the trachea was significantly thicker in the group with topical mitomycin-C application compared to the control group (p<0.01).

Conclusion: Topically applied mitomycin-C following tracheal surgery slows down epithelization and, thus, decreases the development of granulation tissue and maintains a wider diameter of the trachea.