Fluoroscopy guided electrode-array insertion for cochlear implantation with straight electrode-arrays: a valuable tool in most cases.

ABSTRACT

PURPOSE: To highlight the advantages of real time fluoroscopy guided electrode-array (EA) insertion (FGI) during cochlear implants surgery. METHODS: All surgical procedures were performed in a dedicated operating room equipped with a robotic C-arm cone beam device, allowing for intraoperative real time 2D FGI and postoperative 3D imaging. Only straight EAs were used. Patients were sorted out in three groups ANAT, with anatomical concerns; HP, with residual hearing; NPR patients with no particular reason for FGI. In all cases the angle of EA-insertion was measured. In the HP group pre and postoperative hearing were compared. The radiation delivered to the patient was recorded. RESULTS: Fifty-three cochlear implantation procedures were achieved under fluoroscopy in 50 patients from November 2015 to January 2020 (HP group n = 10; ANAT group n = 13; NPR group n = 27). In the ANAT group, FGI proved to be helpful in 8 cases (61.5%), successfully guiding the surgeon during EA -insertion. On average, the angle of insertion was at 424° ± 55°. In the HP group, a controlled smooth EA-insertion was carried out in all cases but one. The targeted 360° angle of insertion was always reached. Hearing preservation was possible with an eventual average drop of 30 ± 1.5 dB. In the NPR group, FGI helped control the quality of insertion in all cases and appeared very informative in five (17.8%) one EA-misrouting, three stuck EAs, and one case with hidden electrodes out of the cochlea in revision surgery. Final 3D cone beam CT scan double-checked the EA position in all adults. The radiation dose was equivalent to a bit less than four digital subtract radiographs. CONCLUSION: The FGI is a very useful adjunct in cochlear implantation in all cases of expected surgical pitfalls, in patients with residual hearing, and even in case without preoperative particular reason, with low irradiation.