Fitness of civil aviation passengers to fly after ear surgery.

Movements of the tympanic membrane caused by changes in air pressure are conducted to the ossicles of the middle ear. The gliding mechanism of the malleus-incus articulation converts in-and-out movements of the eardrum into up-and-down movements of the stapes, thereby protecting the inner ear from static pressures. In certain ear operations, the replacement of a middle ear ossicle by a prosthesis disjoints the malleus-incus articulation or makes it rigid. Pressure is then transmitted in unattenuated form from the eardrum through the oval window to the inner ear. Impairment of pressure equilibration, for example due to obstructed eustachian tubes, can lead to prosthesis displacement with severe injury to the vestibulocochlear apparatus. Thus, patients should be advised to begin equilibration of pressure at the beginning of descent of commercial airlines or civil aviation flights, and to repeat it a brief intervals.