[Is measuring impedance following ear operations an aid in the analysis of postoperative sequelae?]

While the diagnostic value of pre-operative tympanometry is undisputed, there are very few publications on its application in postoperative control of sound conduction development. We measured otoadmittance several times after middle ear surgery in 42 cases. A significant increase of maximal admittance is found over a period of up to 24 months in case of tympanoplasty type I (16 cases, Fig. 1), and after stapedectomy (8 cases, Fig. 3). After a tympanoplasty of type III (Wullsteins classification) many tympanograms were flat, even in the follow-up examination, but a tendency to improvement can also be observed (Fig. 2). In none of the groups was hearing loss correlated with otoadmittance. Thus, tympanometry is not suitable for postoperative evaluation of conductive hearing loss. Nevertheless, our results indicate that the healing process after tympanoplasty modifies middle ear sound transmission for quite a long time.