Impedance-development with direct-fitting after cochlear implantation
23 April 2019 (online)
Normally, the patient's cochlear implant will be fitted approximately 4 weeks postoperatively. Both the literature and our own experience have shown that a cochlear implant can be activated early without risk even after the first post-operative day (direct-fitting). It is known that the lack of electrical stimulation after implantation leads to an increase in impedance. It is thought that this may be a sign of fibrosis. In our first impedance study we have already compared the impedance of 2 groups, a DA group (patients with direct activation/fitting 2 days after implantation) and a control group (patients with initial activation/fitting, about 1 month after implantation). There was a tendency for lower impedances in the DA group. A significant difference could not be found.
We have compared 2 groups
the DA group (patients with direct fitting 2 days after implantation), n = 33.
The Control group (patients with initial fitting, approximately 1 month after implantation), n = 35. The impedance values of both groups (with subgroups Advanced Bionics, Cochlear and Medel) are compared.
Preliminary results show that the impedance values at the time of the 3-month and 6-month control show no significant differences between the two groups.
There was no significant difference in impedance values in our study. This may mean that the fibrosis that occurs after cochlear implantation again partially disappears. But it can also mean that the direct fitting can not prevent fibrosis. In order to determine this, further research (preferably animal studies) would be necessary.