Investigating the Effect of Cochlear Size in Insertion of Electrode Depth in Patients with Cochlear Implantation evaluated by CT-Scan

Background
Cochlear implant surgery is an invasive procedure for patients with bilateral Sensorineural hearing loss and may cause some risks such as cochlear damage. We aimed to evaluate the effectiveness of cochlear measures obtained by computed tomography (CT) scan in predicting depth of cochlear implant insertion.
Materials and Methods
This study was conducted in a retrospective and cross-sectional study on 39 patients undergoing cochlear implantation with MED-EL Device. High-resolution radiographs provided preoperative by CT-Scan were used to determine electrode array insertion depth and diameter of the cochlea’s basal turn. The insertion was considered deep when the electrode was placed at least 22 mm into the cochlea. Demographic data, CT-Scan results and cochlear implantation outcomes (deep or shallow) were evaluated. Data were analyzed by SPSS22 software and the significance level was less than 0.05.
Results
The mean age of patients was 8.026±1.77 years. The depth of insertion of the electrode in 34 (87.18%) patients was deep and in 5 (12.82%) patients was shallow that the difference was statistically significant (P<0.05). Mean size of cochlear in deep group was significantly higher than shallow group (5.89±0.39 vs. 5.2±0.25 mm respectively). There was a significant relationship between age and gender of patients in deep group, which females and patients with lower age reported a higher level of shallow insertion.
Conclusion
The results of present study showed the efficacy of using CT-Scan before surgery to predict the depth of implant placement and help it to select the appropriate prosthesis