Role of Pre-Operative High-Resolution Computed Tomography for Surgical Planning in Patients Undergoing Cochlear Implantation - An Observational Study.

BACKGROUND

Currently preoperative magnetic resonance imaging (MRI) brain and High-Resolution Computed Tomography (HRCT) scanning of temporal bones form part of routine Cochlear implantation (CI) assessment. Pre- operative imaging demonstrates anatomic details or anomalies if any, that prove essential in pre-surgical evaluation of patients. These form a road map for the surgeon to anticipate any difficulty during surgery, to aid in decision making to implant the most appropriate ear, plan surgical technique, or select electrode arrays.

METHODS

A descriptive observational pilot study was conducted at tertiary care hospital involving 51 paediatric patients worked-up for CI. Patients after detailed clinical evaluation and MRI Brain, a tentative surgical plan was formulated by a candidacy CI screening committee. Patients selected for surgery underwent HRCT temporal bones and surgical plan was modified after analysing the same. Percentage of cases in which surgical plan changed (in terms of laterality of surgery) after correlating with HRCT findings were determined and data analysed.

RESULTS

A total of 51 patients worked up for CI were included in the study. In 37.3% cases, there were unfavourable MRI findings. HRCT scan was used to aid the surgical road map in these patients, which based on MRI findings would have had suboptimal outcome.

CONCLUSION

With this understanding, we recommend that, MRI with precise interpretation would be sufficient to furnish all necessary information in preoperative assessment of CI patients, and a HRCT temporal bones maybe indicated only in difficult cases or those with unfavourable MRI findings, may aid predict surgical events.