Treatment of chronic tympanic-membrane perforations with a platelet-derived releasate

Purpose: Tympanic membrane perforations are very common and often require surgical treatment. Recent studies have suggested that growth factors may be an effective nonsurgical alternative for treating chronic perforations. The purpose of this study was to assess the efficacy of a platelet releasate in the treatment of chronic nonhealing perforations in the chinchilla model. Methods: Bilateral perforations were created in 47 chinchillas by excising 80% of the tympanic membrane with a thermal myringotomy knife. Bilateral perforations >50% of its surface area persisted for 10 weeks in 34 animals, and unilateral perforations >50% of its surface area, in nine animals. Only animals with bilateral chronic perforations were included in this study. After deepithelializing the perforation and packing the middle ear and external ear canals with Gelfoam, we treated the perforations with either platelet releasate or buffered saline. Each animal served as its own control. Results: The tympanic membranes were evaluated over a 12-week period by microscopy, photography, tympanometry, and histology. No statistical difference between treated and control ears in the incidence of perforation closure was evident. Histologically, the treated tympanic membranes consistently had a thicker fibrous layer than the controls. Conclusions: These data suggest that platelet releasate is not effective in enhancing closure of chronic tympanic membrane perforations in the chinchilla model.