gms | German Medical Science

To evaluate the feasibility of rotational tomography in cochlear implant patients for assessment of intracochlear electrode position.

Adult patients, that underwent cochlear implant surgery (Nucleus Contour array and Nucleus Contour Advance electrode) were examined by means of rotational tomography. Quality of imaging and intracochlear electrode position were evaluated with regard to insertion into scala tymani, scala vestibuli and possible dislocation of the electrode array.

The intracochlear electrode position could be determined in all cases. In that, reconstruction techniques such as multiplanar reconstructions and curved reformations were essential for assessment of electrode position. Whilst the Nucleus Contour array was characterized with a high rate of dislocations from scala tympani to scala vestibuli and an unexpected high rate of scala vestibuli insertions the Nucleus Contour Advance array showed a more consistent position of the electrode array within the scala tympani without dislocations. Moreover the rate of scala vestibuli insertions was reduced.

RT was able to demonstrate the electrode position within the human cochlea after cochlear implant surgery in all patients. As such RT is available as a tool for quality control after human implantation. Evaluation of electrode position showed different results in using the Nucleus Contour and Nucleus Contour Advance electrodes. Possible mechanisms that contribute to our observations are changes of electrode design and a more consistent surgical technique resulting in an increased rate of scala tympani insertions without dislocation.