Problems and improvements in cochlear implant surgery.

Cochlear implant surgery has been reported to be easy to perform. We have performed cochlear implantation on eight deaf patients and experienced some difficulties. In order to make this surgery easier, the following points must be kept in mind. 1) Before the operation CT and MRI must be done in order to determine the condition of the cochlea. To determine the condition of the round window, probe tympanotomy was performed at least one month before the operation. 2) After setting the electrode in the cochlea, an X-ray film should be taken to confirm that the electrode is suitably positioned in the cochlea.