Safety and efficacy of topical mitomycin C in myringotomy patency.

OBJECTIVE

To develop an alternative method for prolonged middle ear ventilation using topical mitomycin C.

STUDY DESIGN AND

SETTING

Twenty guinea pigs with normal ears had bilateral myringotomies performed using the argon laser. After myringotomy, either mitomycin C (0.4 mg/mL) or saline pledgets were applied topically. Monitoring consisted of otomicroscopy and distortion-product otoacoustic emissions.

RESULTS

Before myringotomy, all tympanic membranes were intact, and distortion-product otoacoustic emissions were measurable. After myringotomy, none (0%) of the saline-treated myringotomies were patent at day 7 as compared with 100% of the mitomycin C-treated myringotomies. At day 42, 10 (52.6%) of 19 mitomycin-treated myringotomies remained patent and 4 (28.6%) of 14 were patent at 131 days. Five (13.1%) ears developed purulent otorrhea; 3 were mitomycin C-treated and 2 were treated with saline solution.- Distortion-product otoacoustic emissions testing did not document any evidence of ototoxicity.

CONCLUSION

Topical mitomycin C appears to be safe and effective at prolonging the duration of myringotomy patency in the guinea pig.

SIGNIFICANCE: Mitomycin C may be useful as an adjunct for preventing myringotomy closure.