Effects of topical application of mitomycin-C and 5-fluorouracil on myringotomy in rats.

Objective: The effects of topical application of Mitomycin-C (MMC) and 5-fluorouracil (5-FU) for maintaining myringotomy patency were investigated in this experimental study.

Study Design: We performed simple myringotomy with a knife on 140 tympanic membranes of 70 rats. Rats were divided in two study groups and a control group. Each study group had 60 tympanic membranes, and the control group had 20. We applied Mitomycin-C (0.4 mg/ml) in Group A, 5-fluorouracil (50 mg/ml) in Group B topically, and sterile saline in the control group for 10 minutes. Examination was made with otoendoscope on days 1, 3, 5, 7, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, and 70, and patency rates were recorded.

Results: MMC and 5-FU Groups remained open for a mean of 46.17 days and 14.62 days, respectively. The control ears healed within 10.4 days. Fibrosis of the MMC-treated group was the same as that of 5-FU-treated groups. Fibrosis of both study groups was significantly lower than that of the control group.

Conclusions: MMC is more effective than 5-FU, which is more effective than the simple myringotomy procedure in extending the patency of myringotomies in rat tympanic membranes (p < 0.05). Both medications are useful as an adjunct in preventing myringotomy closure.