Evaluation of the regenerative capacity of the tissues of the external auditory canal and tympanic membrane in patients with chronic otitis media

Abstract

Relevance: It is noted that the condition of the skin, the external auditory canal bone, the eardrum residues, that is, the tissues, from which the graft must first receive nutrition, largely determine the myringoplasty result. Purpose: to assess the regenerative ability of the external auditory canal and tympanic membrane tissues in patients with chronic otitis media. Materials and Methods: The migration ability of the external auditory canal and tympanic membrane tissues study was carried out in 98 patients with acute tympanic membrane perforation using a tissue staining test. In patients with chronic otitis media the staining test was performed before the operation. The external auditory canal skin in the bone part and the tympanic membrane residues were taken in patients of all groups in myringoplasty for immunohistochemistry. The quantitative assessment of the biomolecular markers expression was performed by the digital image analyzing. It was obtained by a Leica DMLS microscope with software (Germany) and a JVC digital camera (the magnification of 200 times and a minimum number of view fields 5 in each microslide) using «positive pixel count» and morphometry software Aperio Image Scope. Results: It was noted that in cases where the perforation was not closed, the migration ability of the tissues was impaired. A correlation was established between the regenerative ability of the epithelium by determining tissue biomarkers and migration ability. A high EGF level indicates a good regenerative ability and a positive test with staining. A low EGF level is noted in a negative test with staining. The state of the migratory ability of the external auditory canal epithelium and the tympanic membrane epithelium may indirectly indicate the regenerative ability of tissues and affect the tympanoplasty result. The staining test can serve as a prognostic criterion for the myringoplasty result, because it evaluates the regenerative ability state of the external auditory canal epithelium and eardrum epithelium.