Durability of Hearing Preservation after Cochlear Implantation with Conventional‐Length Electrodes and Scala Tympani Insertion

Abstract

Objectives To analyze factors that influence hearing preservation over time in cochlear implant recipients with conventional-length electrode arrays located entirely within the scala tympani. Study Design Case series with planned chart review. Setting Single tertiary academic referral center. Subjects and Methods A retrospective review was performed to analyze a subgroup of cochlear implant recipients with residual acoustic hearing. Patients were included in the study only if their electrode arrays remained fully in the scala tympani after insertion and serviceable acoustic hearing (≤80 dB at 250 Hz) was preserved. Electrode array location was verified through a validated radiographic assessment tool. Patients with <6 months of audiologic follow-up were excluded. The main outcome measure was change in acoustic hearing thresholds from implant activation to the last available follow-up. Results A total of 16 cases met inclusion criteria (median age, 70.6 years; range, 29.4–82.2; 50% female). The average follow-up was 18.0 months (median, 16.1; range, 6.2–36.4). Patients with a lateral wall electrode array were more likely to have stable acoustic thresholds over time (P < .05). Positive correlations were seen between continued hearing loss following activation and larger initial postoperative acoustic threshold shifts, though statistical significance was not achieved. Age, sex, and noise exposure had no significant influence on continued hearing preservation over time. Conclusions To control for hearing loss associated with inter-scalar excursion during cochlear implantation, the present study evaluated patients only with conventional electrode arrays located entirely within the scala tympani. In this group, the style of electrode array may influence residual hearing preservation over time.

Feasibility of hearing preservation for residual hearing with longer cochlear implant electrodes

“…Other studies have also supported the notion of better hearing preservation among younger patients [11]. Although several studies did not demonstrate any clear evidence regarding the relationship between age and hearing preservation, those study cohorts were based only on adult patients [13]. The hearing level in patients of advanced age seems to deteriorate more than in younger patients after CI surgery, suggesting that the pathophysiology of age-related hearing loss might negatively affect the maintenance of cochlear function.…”

“…EAS has made it possible for them to achieve better hearing; however, they continue to face a considerable issue in terms of the potential risk of deterioration in their residual hearing, which needs to be addressed. As a further consideration, there have been many studies on the use of longer electrodes for hearing preservation [10][11][12][13][14]. In this study, we examined hearing preservation in the low frequency after implantation of electrodes of conventional length for patients who met conventional CI criteria.…”

Predictive factors for short‐ and long‐term hearing preservation in cochlear implantation with conventional‐length electrodes

“…Despite advances in electrode design and increased surgical experience with minimally traumatic techniques, residual hearing is still lost in a considerable number of patients . Various groups have attempted to identify factors that impact hearing preservation, with surgical approach, electrode design, insertion depth, scalar electrode position, age, and inflammation being identified as potentially important factors . Interpreting the relative importance of these variables is challenging due to significant heterogeneity among studies in how hearing preservation is defined.…”

“…6 Various groups have attempted to identify factors that impact hearing preservation, with surgical approach, electrode design, insertion depth, scalar electrode position, age, and inflammation being identified as potentially important factors. [7][8][9][10] Interpreting the relative importance of these variables is challenging due to significant heterogeneity among studies in how hearing preservation is defined. To this end, the authors assert that maintenance of functional hearing-hearing that can be successfully aided acoustically-should be the most important consideration in reporting hearing preservation outcomes.…”

Highlights from the Current Issue

“…2 The authors examined 16 patients in their practice who met inclusion criteria for their study, and they examined their acoustic thresholds over time to assess stability. While the study was small in scope, it did suggest that patients who were implanted with a lateral wall electrode array were significantly more likely to have stable acoustic thresholds over time.…”