Cochlear implant electrode insertion complication in a group of over 300 paediatric recipients

Objective: Electrode tip fold-over (TFO) represents a complication of cochlear implantation. TFO may lead to insertion trauma and malfunction of the cochlear implant (CI), often requiring re-implantation. It is mostly associated with pre-shaped CI electrodes.Methods: Our aim was to provide a systematic literature review to examine the current rate of electrode TFO with different commercially available electrode types and compare it with our clinical experience. We performed a retrospective analysis of 370 paediatric CI patients up to 19 years of age, who underwent surgery at our department between 2014 and 2024. We studied laterality, diagnostic findings that revealed a TFO, and subsequent therapeutic solutions.Results: Intraoperative plain film X-ray and neural response telemetry (NRT) were performed during surgeries. In total, 585 ears were operated (unilateral, metachronic, and synchronic bilateral implantation). Straight electrodes were used in 26.3% and pre-shaped electrodes in 73.7% of surgeries. TFO was diagnosed in 17 cases (2.8%), including 11 male (65%) and 6 female (35%) patients. Most TFO complications were caused by pre-shaped electrodes (15 out of 17). There were 14 TFOs on the right side and 3 on the left. TFO was diagnosed mostly by X-ray. NRT was not proven to be a reliable method to detect a TFO.Conclusions: According to our review of 7550 CI surgeries, TFOs were identified in 222 ears with pre-shaped electrodes (4.2% incidence) and 13 ears with straight electrodes (0.57% incidence). In our cohort, the total occurrence of TFO was 2.8%, predominantly caused by pre-shaped electrode arrays compared to straight arrays.