Safety and efficacy of topical mitomycin C in myringotomy patency

OBJECTIVE: To develop an alternative method for prolonged middle ear ventil ation 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 m itomycin C (0.4 mg/mL) or saline pledgets were applied topically, Monitorin g consisted of otomicroscopy and distortion-product otoacoustic emissions. RESULTS: Before myringotomy, all tympanic membranes were intact, and distor tion-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%) o f 19 mitomycin-treated myringotomies remained patent and 4 (28.6%) of 14 we re patent at 131 days. Five (13.1%) ears developed purulent otorrhea; 3 wer e mitomycin C-treated and 2 were treated with saline solution. Distortion-p roduct otoacoustic emissions testing did not document any evidence of ototo xicity, CONCLUSION: Topical mitomycin C appears to be safe and effective at prolong ing the duration of myringotomy patency in the guinea pig. SIGNIFICANCE: Mitomycin C may be useful as an adjunct for preventing myring otomy closure.