The Concept of Individual Partial Electrode Insertion in Patients with Functional Residual Hearing

Background In patients aiming for a hearing preservation cochlea implantation the surgeon faces the choice of the best modality (electric-acoustic stimulation (EAS) or electric stimulation (ES)) and correct electrode length. A partial electrode insertion can combine the advantages of short electrodes – good hearing preservation results– and of long electrodes – higher cochlear coverage. Firstly, a longer electrode is partially inserted aiming for EAS and allows in case of progressive hearing for an afterload of the electrode for ES. Furthermore, the insertion depth can determined individually taking patient specific factors, as hearing thresholds, cochlear geometry and medical history into account.

Methods In total, n=35 patients were treated with partial insertion. Hearing preservation and speech perception in noise post implantation were examined.

The procedure for determination of a patient specific insertion depth was implemented into a software tool, which allows the prediction of the postoperative hearing loss and electrode position. It was used in 5 cases, by now.

Results Patients treated with a partial insertion showed a median hearing loss of 15 dB (n=35) at first activation and 12 dB (n=27) at 6 months. n=24 patients could use the residual hearing for EAS and achieved in median 88% (n=24) in HSM sentence in noise (10 dB SNR) at 6 months.

Discussion Patients with residual hearing can benefit from partial insertion. They achieve very good hearing preservation results and excellent speech perception results in noise with EAS. An individual partial insertion allows for a patient specific selection of the electrode insertion depth. The prediction tool supports the surgeon with the choice of the individual insertion depth.

Poster-PDF A-1676.PDF

Publication History

Article published online:
10 June 2020