Clinical significance of stapedioplasty biomechanics: swimming, diving, flying after stapes surgery.

A piston prosthesis in stapedioplasty significantly modifies the function of the normal ossicular chain. Due to the fact that the ear works as a pressure receptor, a piston prosthesis will be displaced at ambient air pressure changes in a different way than the normal stapes. Our ear is constantly exposed to these pressure changes in daily live, for example during swallowing, with tubal opening, with wind gusts at the external ear, during flying, or diving. Temporal bone experiments showed that elevated static pressures, like in tympanometry, can displace a piston up to 0.5mm in the vestibule. These large movements, which are caused by the missing attachment of the piston to the annual ligament, may explain why a short piston can be lifted out of the footplate perforation (e.g. after sneezing) or a piston with excessive length might come into contact with the membranous labyrinth, causing vertigo with an inward movement. Flying or diving can be performed by the patients after stapedioplasty, provided that a test with tympanometry is tolerated without evoking vertigo.