TREATMENT OF CHRONIC TYMPANIC-MEMBRANE PERFORATIONS WITH A PLATELET-DERIVED RELEASATE

Purpose: Tympanic membrane perforations are very common and often requ ire surgical treatment. Recent studies have suggested that growth fact ors may be an effective nonsurgical alternative for treating chronic p erforations. The purpose of this study was to assess the efficacy of a platelet releasate in the treatment of chronic nonhealing perforation s in the chinchilla model. Methods: Bilateral perforations were create d in 47 chinchillas by excising 80% of the tympanic membrane with a th ermal myringotomy knife. Bilateral perforations >50% of its surface ar ea 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 deepithelializ ing the perforation and packing the middle ear and external ear canals with Gelfoam, we treated the perforations with either platelet releas ate or buffered saline. Each animal served as its own control. Results : The tympanic membranes were evaluated over a 12-week period by micro scopy, photography, tympanometry, and histology. No statistical differ ence between treated and control ears in the incidence of perforation closure was evident. Histologically, the treated tympanic membranes co nsistently had a thicker fibrous layer than the controls. Conclusions: These data suggest that platelet releasate is not effective in enhanc ing closure of chronic tympanic membrane perforations in the chinchill a model.