Postoperative Plain Radiographic Evaluation of Electrode Placement After Cochlear Implantation: An Observational Study From India.

Abstract

Despite a rise in the number of cochlear implant (CI) surgeries, limited data is available to date in the Indian settings, on the use of postoperative imaging to confirm intracochlear position of CI electrode array. The current study aims to evaluate the incidence of post-implantation complications related to surgical placement of CI electrode array, as identified on postoperative plain radiographs (X-rays). It also compares the occurrence of such complications amongst different CI manufacturers. The retrospective, observational study incorporated 469 patients (paediatric and adult), who underwent 478 primary cochlear implantations at a tertiary- care CI centre in India, between January 2006 and December 2023. Postoperative day one X-rays were evaluated to check the post-implantation intracochlear position of CI electrode. Angular insertion depths of electrode arrays were measured. Comparison of incidence of electrode related issues was performed amongst devices from four different CI manufacturers used in the study. Postoperative day one X-rays demonstrated normal intracochlear electrode array placement in 93.7 % (448) of the cochlear implantations; whereas electrode-related issues such as kink, incomplete insertion, tip fold-over, basal fold-over, migration and misplacement were identified in 6.3% (30) of the implantations. The percentages of postoperative X-ray abnormalities identified in CI electrodes from Cochlear™ Nucleus® (10.2%) and Oticon Medical (10.5%) were significantly higher than those identified in electrodes from MED-EL (3.8%) and Advanced Bionics (3.7%, p value < 0.05). Assessment of postoperative X-ray findings following CI surgeries conducted over the past 17 years, revealed a statistically significant decline in the overall percentage of electrode-related abnormalities from 12.9% in the years before 2010 to 5.7 % in the subsequent years after 2010 (p-value < 0.05). This study conducted in a large cohort of Indian patients, reiterates that postoperative plain radiography is a simple, reliable, cost-effective imaging technique that can be employed in the Indian settings, to ascertain the post-implantation intracochlear position of CI electrode. Postoperative imaging facilitates optimisation of CI surgery outcomes and leads to timely performance of revision surgeries for correction of electrode position; wherever indicated.

Supplementary information: The online version contains supplementary material available at 10.1007/s12070-025-05555-9.