Intraoperative Evaluation of Cochlear Implant Electrodes Using Mobile Cone-Beam Computed Tomography

<jats:sec> <jats:title>Objective:</jats:title> <jats:p>To evaluate the electrode status during cochlear implantation (CI) using mobile cone-beam CT (mCBCT).</jats:p> </jats:sec> <jats:sec> <jats:title>Study Design:</jats:title> <jats:p>Retrospective case review.</jats:p> </jats:sec> <jats:sec> <jats:title>Setting:</jats:title> <jats:p>Tertiary referral hospital.</jats:p> </jats:sec> <jats:sec> <jats:title>Patients:</jats:title> <jats:p>Fifty-seven patients (7 bilateral surgeries, 64 ears) who underwent CI and who received intraoperative mCBCT imaging.</jats:p> </jats:sec> <jats:sec> <jats:title>Intervention:</jats:title> <jats:p>CI and CBCT during surgery.</jats:p> </jats:sec> <jats:sec> <jats:title>Main Outcome Measure:</jats:title> <jats:p>Electrode location and angular insertion depth determined by intraoperative mCBCT images.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>There were six cases with cochlear malformation where intraoperative mCBCT was useful to confirm electrode location. Of 58 ears with a normal cochlear morphology, perimodiolar, straight, and mid-scalar electrodes were used in 30 (cochleostomy; 14 advance off-stylet technique cases), 27 (26 round window [RW] insertion, 1 extended round window [ERW] insertion), and 1 (RW insertion) ears, respectively. Complete scala-tympani (ST) insertion was achieved in 35 ears (14 cochleostomy, 21 RW or ERW insertion). The complete ST-insertion rate was significantly higher with RW or ERW insertion than that for cochleostomy insertion (<jats:italic toggle="yes">p</jats:italic> = 0.03), although cochleostomy insertion using the advanced off-stylet technique had a similar rate to RW or ERW insertion. The angular insertion depth values (average ± standard deviation) for perimodiolar electrodes (354.4 ± 29.44 degrees) were significantly smaller than those for Flex24 (464.8 ± 43.09 degrees) and Flex28 (518.2 ± 61.91 degrees) electrodes (<jats:italic toggle="yes">p</jats:italic> < 0.05).</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions:</jats:title> <jats:p>Evaluation of CI electrodes using intraoperative mCBCT was comparable to that with fan-beam CT or c-arm-based CBCT. Considering the low radiation dose of mCBCT and its availability in any operation room, mCBCT is the better modality for evaluating cochlear implant electrode arrays.</jats:p> </jats:sec>