[The analysis of the electrode impedance in different periods after cochlear implantation performed with round window insertion in steroid deposition].

To study the variation of the electrode impedance in different periods after cochlear implantation performed with round window insertion in steroid deposition, and to provide the basis for the postoperative debugging of the speech processor. Detected the electrode impedance of 47 cochlear receivers after operation in steroid deposition from September 2014 to October 2015, compared the impedance values between different periods, and different groups according to their locations. The average impedance of all the electrodes and the 3 subgroups are low after implantation (period A0), peaked at the first month (period A1), then decreased slowly, and then turned to be stable at the sixth month (period A3); the impedance values were no significantly different between the sixth month (period A3) and the twelfth month (period A4) while were significantly different between each of other two periods (<0.05); the apical group had the highest impedance and the basal group had the lowest impedance in all the 5 periods. The local use of steroid can decrease the impedance of the electrode after implantation. The impedance value were the low during operation, peaked at the first month, then decreased slowly, and turned to be stable at the sixth month. As a result, the cochlear implant should be debugged at regular intervals in 6 months after operation to obtain the best hearing status.