Role of the Eustachian Tube Occlusion in Subtotal Petrosectomy: Long-Term Results and Influential Factors

Background: Eustachian tube (ET) closure during subtotal petrosectomy (STP) serves for sealing the middle ear cleft from the nasopharynx and prevents infection.

Objective: The aim of this study was to evaluate the success of Eustachian tube (ET) occlusion in subtotal petrosectomy in relation to the occlusive material and the topographic anatomy of the pars ossea.

Patients and Methods: We evaluated all cases of subtotal petrosectomy with abdominal fat obliteration carried out by one surgeon at single tertiary care referral center. Only cases with available cone beam computed tomography prior to cochlear or middle ear implantation (in 10 months on average) were included (n = 29). The occlusive material was bone wax with either muscle tissue (n = 12) or oxidized regenerated cellulose (Tabotamp) (n = 17). The occlusion success was also evaluated in relation to the topography between the basal cochlear turn and the carotid canal. The measurements were done in standardized alignment using curved three-dimensional multiplanar reconstruction.

Results: In 31 % of the cases there was air in the obliteration cavity indicating insufficient occlusion of the ET. In none of these cases an infection of the fat filling was observed during the implantation procedure. The failure rate between both occlusion techniques (using Tabotamp 29.4 % or own muscle tissue 33.3 %) showed no significant difference. The topographical relation of the above-mentioned landmarks varied from overlapping (max. 3.1 mm) to detachment (max. 5.3 mm). An insufficient occlusion could be seen for both techniques in cases with detachment as well as with overlapping.

Conclusions: An incomplete occlusion of the Eustachian tube alone does not lead to an infection of the obliteration cavity. The muscle tissue as autogenic tissue is just as suitable for tube occlusion as Tabotamp which is alloplastic material. The topographical variance of the occlusion site seems to have no influence on the long-term success of the ET occlusion.