Diagnostic accuracy of tubomanometry R value in detecting the Eustachian tube pressure equalizing function.

Tubomanometry is a relatively novel Eustachian tube (ET) function testing method. A number of recent studies have utilized the R value of Tubomanometry as the main objective measure in reporting their outcome in balloon dilation of ET. There is, however, a lack of evidence concerning the reliability or validity of Tubomanometry measurements. The objectives of this study are to determine the accuracy of Tubomanometry for detecting ET opening as compared to tympanometry and determine its usefulness as a measure of ET function. Healthy subjects between ages 8 and 76 years with an intact tympanic membrane and no middle ear (ME) effusion were prospectively tested. Primary outcomes were the ET opening as determined by the Tubomanometry R value and the increase in ME pressure with tympanometry-measured in relation to a swallow at a nasopharyngeal pressure of 300 daPa. The accuracy of the tubomanometry R value for identifying a successful ET opening was made in reference to the change of ME pressure. A total of 280 measurements were available from 258 ears in 137 subjects. The presence of tubomanometry R value showed high sensitivity of detecting ET opening for the criteria of >5 daPa ME pressure increase (187/202) but low specificity for detecting ET non-opening (34/78). The R value criterion described in the original manuscripts on Tubomanometry is sensitive but not specific for ET opening. The need for validation of the tubomanometry test obviates its use as the main objective outcome measure for the balloon dilation of ET procedure.