Middle Ear Ventilation Mechanism

Evaluation of Eustachian tube function with ventilation scintigraphy by using133Xe gas

“…The Eustachian tube has two important roles, ventilatory and clearance functions. Various methods are employed for the examination of Eustachian tube function, namely the inflation/deflation test, sonotubometry, tubo-tympano-aerodynamic graphy (Kumozawa et al, 1990;Shimada et al, 1990;Yamashita et al, 1990;Monsell and Harley, 1996); however, no test has achieved universal acceptance. Kumozawa et al (1990) suggested that from the clinical viewpoint, the function test must be simple to operate and not too dependent on whether or not a perforation is present in the tympanic membrane.…”

“…When performing Valsalva manoeuvres, the tubes do not open in all patients to let air into the tympanum (Brenner et al, 1997). In particular, a locking can occur when overpressure becomes too high in the nasopharynx and they do not open without swallowing (Flisberg, 1966;Yamashita et al, 1990;Brenner et al, 1997). The opening of the Eustachian tube depends on the position of the subjects.…”

“…Various methods are employed for the examination of Eustachian tube function. Inflation/deflation test, sonotubometry and tubo-tympano-aerodynamic graphy are some of the reported methods for examination of Eustachian tube function (Kumozawa et al, 1990;Shimada et al, 1990;Yamashita et al, 1990). But superiority between them remains obscure.…”

“…In order to gain a clearer picture of the middle ear ventilation and Eustachian tube function many studies on gas transport have been carried out by indirect methods, for example, by observing pressure changes in the middle ear by insufflation of various gases. One reason for the weakness in this research field might be that gases cannot be observed directly (Jones, 1961;Cantekin et al, 1980;Shimada et al, 1990;Yamashita et al, 1990). However, ventilation scintigraphy techniques, using radioactive gases, make it possible to observe their images.…”