Effect of early activation of cochlear implant on electrode impedance in pediatric population

Early activation of active middle ear implants: a prospective study

PURPOSE

Vibrant Soundbridge (VSB) is an active middle ear implant that serves as a solution for people unable to use conventional hearing aids properly. Surgical techniques for VSB implantation have progressively advanced, improving its outcomes. Traditionally, VSB processor activation transpires around four weeks after the surgery to provide enough healing; however, contemporary practices in cochlear implant and bone-anchored hearing device activations indicate reduced waiting times. The purpose of this research is to explore the feasibility, safety, and advantages of early VSB activation.

METHODS

This prospective study was conducted in two phases. In phase one, the patients only attempt using the device on the first business day after surgery and then return in 4 weeks for a complete and standard fitting and device use. In the second phase, participants had a thorough fitting and began using the device on a regular basis the first working day after surgery. Feasibility, safety, and audiological results were assessed throughout both phases.

RESULTS

Early activation was successfully achieved in all patients in the early group without significant complications. When comparing the audiological examination and fitting parameters between the initial session the day after surgery and the one-month follow-up, there was no statistically significant change.

CONCLUSION

The study emphasizes the possibility for early VSB activation, which might minimize wait times and enhance patient satisfaction without compromising device function. Further study is required to validate these results in broader groups and investigate long-term consequences.

Bilateral Simultaneous Cochlear Implants: How Early Activation Influences Wearing Hours

Background/Objectives: Cochlear implantation (CI) is a transformative intervention for individuals with sensorineural hearing loss, providing auditory and speech perception improvements. Traditional CI activation occurs 4-6 weeks post-surgery; however, recent advancements allow for early activation within 1-2 days. The integration of data logging in modern CI systems offers objective insights into processor usage and auditory exposure, which are crucial for optimizing rehabilitation outcomes. Methods: A retrospective study was conducted on 63 patients with bilateral simultaneous CIs using MED-EL SONNET2/RONDO3 devices. Patients were classified into early activation (n = 30, activation within 1-2 days) and classical activation groups (n = 33, activation after day 2). Data logging metrics, patient demographics, and implant details were analyzed using the Wilcoxon rank-sum test and Poisson regression. Results: Daily processor usage did not significantly differ between groups (9.5 ± 3.0 h/day for classical vs. 9.4 ± 3.7 h/day for early activation, p = 0.927). Subgroup analysis showed a significant 18% increase in processor usage with each additional year of patient age (IRR = 1.18, p < 0.001) and a 15% decrease in usage with each year delay in implantation age (IRR = 0.85, p < 0.001) among early activation users. Switch-on frequencies were comparable between groups, with no significant differences observed (p = 1.0). Conclusions: Early activation is feasible and associated with consistent CI usage, providing potential benefits in auditory rehabilitation. Future research should explore its impact on long-term speech and language outcomes to inform evidence-based practices.

Robotic Versus Manual Electrode Insertion in Cochlear Implant Surgery: An Experimental Study

OBJECTIVES

This experimental study compared the precision and surgical outcomes of manual versus robotic electrode insertions in cochlear implantation.

METHODS

The study was conducted on formalin-fixed cadaveric heads, with nine senior neurotologists performing both manual and robotic insertions.

RESULTS

The results showed no statistically significant differences between the two methods in terms of insertion angle, cochlear coverage, or electrode coverage. However, the robotic method demonstrated a significantly slower and more controlled insertion speed (0.1 mm/sec) compared to manual insertion (0.66±0.31 mm/sec), which is crucial for minimizing intra-cochlear force and pressures. Although robotic insertions resulted in fewer complications such as tip fold-over or scala deviation, there were instances of incomplete insertion.

CONCLUSION

The robotic system provided a consistent and controlled insertion process, potentially standardizing cochlear implant operations and reducing outcome variability. The study concludes that robotic-assisted insertion offers significant advantages in controlling insertion speed and consistency, supporting the continued development and clinical evaluation of robotic systems for cochlear implant surgery.

Cochlear Implantation: Long-Term Effect of Early Activation on Electrode Impedance

Objectives: The growing adoption of cochlear implants (CIs) necessitates understanding the factors influencing long-term performance and improved outcomes. This work investigated the long-term effect of early activation of CIs on electrode impedance in a large sample of CI users at different time points. Methods: A retrospective study on 915 ears from CI patients who were implanted between 2015 and 2020. According to their CI audio processor activation time, the patients were categorized into early activation (activated 1 day after surgery, n = 481) and classical activation (activated 4 weeks after surgery, n = 434) groups. Then, the impact of the activation times on the electrode impedance values, along the electrode array contacts, at different time points up to two years was studied and analyzed. Results: The early activation group demonstrated lower impedance values across all the electrode array sections compared to the classical activation at 1 month, 1 year, and 2 years post-implantation. At 1 month, early activation was associated with a reduction of 0.34 kΩ, 0.46 kΩ, and 0.37 kΩ in the apical, middle, and basal sections, respectively. These differences persisted at subsequent intervals. Conclusions: Early activation leads to sustained reductions in the electrode impedance compared to classical activation (CA), suggesting that earlier activation might positively affect long-term CI outcomes.

Early fitting in cochlear implant surgery: preliminary results

PURPOSE

Cochlear implants are usually activated 3-5 weeks after surgery; to date, no universal protocol exists regarding switch on and fitting of these devices. The aim of the study was to assess safety and functional results of activation and fitting of cochlear implant within 24 h following surgery.

METHODS

In this retrospective case-control study, 15 adult patients who underwent cochlear implant surgery, for a total of 20 cochlear implant procedures were analyzed. In particular, clinical safety and feasibility were investigated by examinating patients at activation and at each follow-up. Values of electrodes' impedance and most comfortable loudness (MCL) were analyzed from the time of surgery to 12 months after activation. Free-field pure tone average (PTA) was also recorded.

RESULTS

No major or minor complications were reported and all patients could perform the early fitting. Activation modality influenced impedance values only in the short term but the differences were not statistically significant (p > 0.05). Mean MCL values in the early fitting group were lower than MCL of the late fitting in all follow-up sessions, and the difference was statistically significant (p < 0.05). The mean PTA was lower in the early fitting group but the difference was not statistically significant (p < 0.05).

CONCLUSIONS

Early fitting of cochlear implants is safe, allows for an early rehabilitation and can have possible beneficial effects on stimulation levels and dynamic range.

Early activation of cochlear implants: a systematic review and narrative synthesis

BACKGROUND

Device activation typically occurs four weeks post cochlear implant surgery. Emerging evidence suggests earlier activation is feasible and beneficial, giving patients quicker access to sound and rehabilitation.

OBJECTIVES

Assess current literature for effects of early cochlear implant activation.

METHODS

Electronic searches of Medline/PubMed, AMED, EMBASE, CINAHL and the Cochrane Library following PRISMA guidelines. Studies investigating any aspect of early activation were included for review.

RESULTS

From 15 studies, 625 patients received early activation, compared with 243 patients in the control groups. Early activation was considered as within 7 days post-operatively with 12 studies reporting within 1 day post-operatively, compared with standard activation of 9-46 days post-operatively in the control group. Some studies indicated earlier low levels of impedance in the early activation group. Magnet strength adjustment or off-ear processor wear was often recommended within the early activation cohort. Complication rates were low in both groups. Early activation improved patient satisfaction and anxiety levels without detriment to speech recognition or rehabilitation.

CONCLUSION

Early cochlear implant activation is feasible and allows patients with no contraindications, earlier access to auditory perception and rehabilitation and reduces anxiety linked to delay in activation. Further evidence is required to monitor long-term effects of early activation.

Postoperative Impedance-Based Estimation of Cochlear Implant Electrode Insertion Depth

OBJECTIVES

Reliable determination of cochlear implant electrode positions shows promise for clinical applications, including anatomy-based fitting of audio processors or monitoring of electrode migration during follow-up. Currently, electrode positioning is measured using radiography. The primary objective of this study is to extend and validate an impedance-based method for estimating electrode insertion depths, which could serve as a radiation-free and cost-effective alternative to radiography. The secondary objective is to evaluate the reliability of the estimation method in the postoperative follow-up over several months.

DESIGN

The ground truth insertion depths were measured from postoperative computed tomography scans obtained from the records of 56 cases with an identical lateral wall electrode array. For each of these cases, impedance telemetry records were retrieved starting from the day of implantation up to a maximum observation period of 60 mo. Based on these recordings, the linear and angular electrode insertion depths were estimated using a phenomenological model. The estimates obtained were compared with the ground truth values to calculate the accuracy of the model.

RESULTS

Analysis of the long-term recordings using a linear mixed-effects model showed that postoperative tissue resistances remained stable throughout the follow-up period, except for the two most basal electrodes, which increased significantly over time (electrode 11: ~10 Ω/year, electrode 12: ~30 Ω/year). Inferred phenomenological models from early and late impedance telemetry recordings were not different. The insertion depth of all electrodes was estimated with an absolute error of 0.9 mm ± 0.6 mm or 22° ± 18° angle (mean ± SD).

CONCLUSIONS

Insertion depth estimations of the model were reliable over time when comparing two postoperative computed tomography scans of the same ear. Our results confirm that the impedance-based position estimation method can be applied to postoperative impedance telemetry recordings. Future work needs to address extracochlear electrode detection to increase the performance of the method.

A Literature Review on Cochlear Implant Activation: From Weeks to Hours

Objectives: The present literature review discusses the chronological evolution of Cochlear Implant (CI) activation and its definition among the relevant studies in the literature. In addition, the benefits of standardizing the early activation process in implantation centers worldwide are discussed. Methods: A comprehensive literature search was conducted in the major databases such as PubMed, Scopus, and Embase to retrieve all the relevant articles that reported early activation approaches following CI. Results: The evolution of the timing of early activation after CI has been remarkable in the past few years. Some studies reported the feasibility of early activation 1 day after the CI surgery in their users. Conclusions: Within the last decade, some studies have been published to report the feasibility and outcomes of its early activation. However, the process of early activation was not adequately defined, and no apparent guidelines could be found in the literature.

Cochlear implant electrode impedance subcomponents as biomarker for residual hearing

Introduction and objectives

Maintaining the structural integrity of the cochlea and preserving residual hearing is crucial for patients, especially for those for whom electric acoustic stimulation is intended. Impedances could reflect trauma due to electrode array insertion and therefore could serve as a biomarker for residual hearing. The aim of this study is to evaluate the association between residual hearing and estimated impedance subcomponents in a known collective from an exploratory study.

Methods

A total of 42 patients with lateral wall electrode arrays from the same manufacturer were included in the study. For each patient, we used data from audiological measurements to compute residual hearing, impedance telemetry recordings to estimate near and far-field impedances using an approximation model, and computed tomography scans to extract anatomical information about the cochlea. We assessed the association between residual hearing and impedance subcomponent data using linear mixed-effects models.

Results

The progression of impedance subcomponents showed that far-field impedance was stable over time compared to near-field impedance. Low-frequency residual hearing demonstrated the progressive nature of hearing loss, with 48% of patients showing full or partial hearing preservation after 6 months of follow-up. Analysis revealed a statistically significant negative effect of near-field impedance on residual hearing (-3.81 dB HL per kΩ; p < 0.001). No significant effect of far-field impedance was found.

Conclusion

Our findings suggest that near-field impedance offers higher specificity for residual hearing monitoring, while far-field impedance was not significantly associated with residual hearing. These results highlight the potential of impedance subcomponents as objective biomarkers for outcome monitoring in cochlear implantation.

Early activation after cochlear implantation: a systematic review

PURPOSE

To systematically review the outcomes of early activation following cochlear implantation (CI) based on the findings from different studies in the literature.

METHODS

A comprehensive search strategy was conducted through different databases to identify relevant articles. Our outcomes included impedance levels, rates of complications, hearing and speech perception performance, and patients' satisfaction levels.

RESULTS

The total number of included studies in this systematic review is 19, which recruited 1157 patients, including 857 who underwent early activation following CI. Seventeen studies investigated impedance levels or feasibility rates of early activation approaches. Most of these studies (n = 10) reported that mean impedance levels remarkably decreased within the first day-to-month (first measurement) post-activation. In addition, all 17 studies showed that impedance levels finally normalize and become comparable with intraoperative levels or the conventional activation group. Seventeen studies reported the occurrence of complications in their population. Ten of these studies indicated that none of their patients developed any post-operative complications after early activation. Seven studies reported the development of some minor complications, including pain 9.2% (28/304), infection 4.7% (13/275), swelling 8.2% (25/304), vertigo 15.1% (8/53), skin hyperemia 2.2% (5/228), and others 16.4% (9/55). Hearing and speech perception was assessed in six studies, which showed a remarkable improvement in their patients. Three studies investigated patients' satisfaction and showed high satisfaction levels. Only one report investigated the economic advantages of early activation.

CONCLUSION

Early activation is safe and feasible and does not impact the hearing and speech outcomes of the patients undergoing CI procedures.

Very early activation of cochlear implants: A review of the literature

Cochlear implantation (CI) has become the standard treatment for patients with severe-to-profound hearing loss. To date, an estimated 750,000 individuals spanning the entire lifecycle have benefited from this life-changing technology. Traditionally, the device is not "activated" for 3 to 4 weeks after surgery. However, an increasing number of centers have recently begun to question the conventional wisdom that several weeks are necessary and are activating their patients' device sooner after CI. This review aimed to provide a comprehensive insight to better understand the feasibility, outcomes, benefits, and limitations of very early cochlear implant activation. Data sources from published medical literature were reviewed. A detailed examination and summary were provided. History and safety were also emphasized. It was observed that approximately 20 studies have reported their experience with very early cochlear implant activation, ranging from the day of surgery to 1 week. Outcome measures are disparate, although there is general agreement that early activation is not only feasible but also provides some real-life benefits to patients and caregivers. The surgical, electrophysiological, audiological, and other outcomes were also reviewed. Very early activation is safe and beneficial in patients with cochlear implants. Many CI centers believe that such a process can lead to improvements in both patient-centered and fiscally responsible care. Although not ideal for all patients, cochlear implant programs may consider this option for their patients.

Effect of initial switch-on within 24 hours of cochlear implantation using slim modiolar electrodes

Reducing electrode impedance is an important factor in improving the functional benefits of cochlear implants (CIs). The immediate effect of early switch-on within 24 h of surgery on impedance among CI recipients with various types of electrodes has been reported previously; however, the immediate change and the evolution of electrode impedances of slim modiolar electrodes after early switch-on within 24 h of implantation has not. Therefore, the focus of this retrospective cohort study of CI patients was to compare the effect of early switch-on (n = 36) and conventional switch-on (n = 72) 2–4 weeks post-operation on impedance. Compared with impedance measured intraoperatively, our results demonstrate a significant decrease in impedance from 11.5 to 8.9 kΩ (p < 0.001) at 2–4 weeks after implantation in the early switch-on group, which sharply contrasted with elevated impedance values for conventional switch-on 2–4 weeks after implantation (from 10.7 to 14.2 kΩ, p = 0.001). Notably, a comparatively lower impedance than the conventional switch-on protocol was observed for up to 2 months post-operation. Most importantly, a much earlier stabilization of impedance can be achieved with the early switch-on protocol coupled with the slim modiolar electrode array compared to the conventional switch-on protocol, offering the advantage of reducing the number of required mapping sessions in the early stages of rehabilitation.

Cochlear implant: More hearing better speech performance

BACKGROUND

Datalogging feature of the cochlear implant audio processor has been utilized to calculate the average daily wearing hours for cochlear implant devices by patients.

OBJECTIVES

To assess the relationship between the time use of cochlear implant audio processor and speech development as well as to identify the lowest acceptable duration of audio processor use to achieve an acceptable language development.

METHODS

A retrospective study design including prelingual thirty-four ears (24 patients) who received the same electrode array of cochlear implant with 2 years follow up. The audiological and speech evaluations were done for all patients postoperatively and the last postoperative follow-up visit was used for analysis in this study.

RESULTS

The average daily use of the audio processor was 11.3 ± 2.7 h per day. The pure tone average was 30.55 ± 4.64 dB whereas the speech reception threshold was 30.88 ± 6.12 dB. The average speech discrimination score at 65 dB was 68.59 ± 16.80%. A significant positive correlation (r = 0.54, p value = 0.0009) was found between the daily use of the audio processor and the speech discrimination score. The lowest wearing time needed to have more than 60% of the speech discrimination score was 8.3 h/day.

CONCLUSION

The present study revealed a positive correlation between the daily duration of the audio processor usage and speech performance. Moreover, we found that pediatric patients need to use their cochlear implant device for at least 8.3 h/day to achieve acceptable language development.

Audiological and Speech Performance After Cochlear Implantation in Cochlear Aplasia Deformity

Inner ear malformation is a congenital anomaly associated with prelingual sensory neural hearing loss in the pediatric population. This is a case report of bilateral radiologically diagnosed cochlear aplasia in a child who underwent unilateral left cochlear implantation with audiological results at one-year follow-up after surgery. Sixteen months after the cochlear implantation surgery, the child could produce 200 words and say a sentence with two words. In certain cases of inner ear malformation, the subgrouping of cystic cavity can be difficult and should not delay the trial of cochlear implant provided an acceptable anatomical appearance of the inner ear with cochleovestibular nerve existence and a proper electrode used for implantation.