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 21/2 minutes intraop eratively. Specimens from four patients were collected during surgery and at 15 days, 1 month, 3 months, and 6 months after surgery. The spe cimens were examined under light and electron transmission microscopy and were compared with control specimens. RESULTS: Light microscopy sh owed attenuated epithelium with Subepithelial connective hypocellular. Electron microscopy confirmed these findings and demonstrated swellin g of mitochondria, dilatation of endoplasmic reticulum, and chromatin- dense granules in nuclei of fibroblasts. CONCLUSION: By causing a decr ease in density and cellularity of mucosa, topical use of mitomycin-C may enhance the success of surgery; however, further studies are neces sary to determine the ultimate potential of this agent for this proced ure.