HISTOLOGICAL INVESTIGATIONS OF TYMPANIC MEMBRANE RIM DEFECTS FROM PATIENTS WITH CHRONIC OTITIS-MEDIA

In the present study we investigated resected tympanic membranes taken during tympanoplasty. Tissue from 111 patients with chronic otitis me dia was analyzed after being embedded in paraffin and stained with hem atoxylin and eosin. In 67 patients (60%) the tympanic membrane epiderm is did not extend beyond the margin of the perforation rim, so that no epithelial migration was observed on the inner side of the tympanic m embrane. In 27 specimens (24%) we found an epithelial migration an the inner side of the tympanic membrane, but this did not extend to the m argins of the excised tissue. In 17 tissue specimens (16%) epithelial migration extended to the margins of the resected tissue. Clinically, these patients were found to have non-functioning Eustachian tubes. Th e size of the tympanic membrane perforation was not found to impact on epithelial migration. However,there was a correlation between the ext ent of the epithelial migration seen in the specimens and the occurren ce of a permanent tympanic membrane perforation after tympanoplasty. O f 17 patients with these findings, 4 (23%) had consistent reperforatio ns. The tympanic membrane rims of these patients were completely cover ed with squamous epithelium. Patients with no or only little epithelia l migration to the inner side of the tympanic membrane were found to h ave a significantly lower postoperative rate of recurrent infection an d drum reperforation.