Relationship between middle ear pressure, mucosal lesion, and mastoid pneumatization

Objectives: The inflammatory changes of pneumatic space mucosa are thought to affect the develop ment of pneumatic space and the function of trans muc osal gas exchange. So, it is assumed that the mucosal change is deeply invo lved in the onset and healing process of otitis media with effusion (OME). The objective of this study is to investigate whether the growth of the mas toid cells and the middle ear transmucosal gas exchange function in patient s with OME are affected by the histopathologic changes in middle ear mucosa , and whether these two factors are changed by the treatment of OME. Materi als and Methods: From 65 children with OME, middle ear mucosal specimens we re collected during indwelling of a tympanic tube, and their histopathologi c changes were compared with cell growth area measured on radiographic film s and with the change in the middle ear total pressure (METP), Results: Sup pression of the cell growth area was stronger and the METP stayed lower in cases with a higher degree of mucosal lesion. Significant expansion of pneu matic area was observed after 2 years of tube indwelling, and the peak METP showed a significant increase after 1.5 years. This increase in the METP w as caused by diffusion/absorption of CO2 and O-2 and indicated recovery of the transmucosal gas exchange function, Conclusions: The growth of the mast oid cells and the middle ear transmucosal gas exchange function are closely affected by the subepithelial histopathologic changes in middle ear mucosa , and these two factors recover by the treatment of OME.