Histopathologic effects of mitomycin-C on endoscopic transnasal dacryocystorhinostomy.

Background And Objectives: The antimetabolite mitomycin-C is now being used in endoscopic transnasal dacryocystorhinostomies to prevent the closure of osteotomies.

Patients And Methods: A 0.5-mg/ml solution of mitomycin-C was applied to the osteotomy site for 2 1/2 minutes intraoperatively. Specimens from four patients were collected during surgery and at 15 days, 1 months, 3 months, and 6 months after surgery. The specimens were examined under light and electron transmission microscopy and were compared with control specimens.

Results: Light microscopy showed attenuated epithelium with intracytoplasmic vacuoles. Subepithelial connective tissue was looser and hypocellular. Electron microscopy confirmed these findings and demonstrated swelling of mitochondria, dilatation of endoplasmic reticulum, and chromatin-dense granules in nuclei of fibroblasts.

Conclusion: By causing a decrease in density and cellularity of mucosa, topical use of mitomycin-C may enhance the success of surgery; however, further studies are necessary to determine the ultimate potential of this agent for this procedure.