Chronification of Tympanic Perforation with Mitomycin C in a Rat Model

Background. A rat model of chronic tympanic membrane perforation was developed to be used in the search of new materials for the sealing of these perforations. Methods. A longitudinal study was carried out in rats subjected to incisional myringotomy followed by the application of mitomycin C alone or with dexamethasone. Rats were checked at days 3, 7, 10, 14 and weekly thereafter until perforation closure, for up to 6 months. Results. The addition of dexamethasone is a key component in order to obtain a chronic opening. Myringotomies treated with saline had a mean healing time of 8.5 days. At 8 weeks, 70.5% of these remained perforated and at 6 months this number fell to 21.4%. Conclusion. This technique is able to maintain more than 70% of tympanic membrane perforations patent for at least 8 weeks. This rat model is adequate for its use in preclinical or translational research.