Lower initial electrode impedances in minimally invasive cochlear implantation

The effect of cochlear implant insertion technique on post-operative neural response telemetry and impedance in paediatric patients

OBJECTIVE

This study aimed to compare neural response telemetry and impedance between the round window and cochleostomy approaches for cochlear implantation.

METHODS

In this case-control study, 64 patients aged less than 3.5 years underwent cochlear implantation via the round window or cochleostomy approach. Post-operative neural response telemetry and impedance were measured.

RESULTS

The impedance measurements at electrodes 1, 11 and 22 showed no significant differences between the two groups three months after implantation (p = 0.90, p = 0.08 and p = 0.37, respectively). Similar results were observed six months after implantation (p = 0.71, p = 0.65 and p = 0.70, respectively). There was no significant difference in neural response telemetry between the two groups after three months. The neural response telemetry of electrode 1 in the cochleostomy group (171.26 ± 19.81 μV) was significantly higher in comparison with that of electrode 1 in the round window group (161.97 ± 12.71 μV) after six months (p = 0.03). The neural response telemetry values for electrodes 11 and 22 did not show any significant difference after six months (p = 0.14 and p = 0.48, respectively).

CONCLUSION

Both approaches provide equal stimulation of the cochlear nerve and impedance.