Cochlear re-implant rates in children: 20 years experience in a quaternary paediatric cochlear implant centre

Institutional Experience With Cochlear Implants Falling Under the 2020 FDA Corrective Action

OBJECTIVE

To determine the rate of device failure for those cochlear implants falling under the 2020 Food and Drug Administration (FDA) voluntary corrective action.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary otology-neurotology practice.

PATIENTS

Those with cochlear implant failure falling under the FDA corrective action.

INTERVENTIONS

Cochlear implant explant and reimplantation.

OUTCOME MEASURES

Reason for cochlear implant failure, time to failure, symptoms of failure, and benefit from reimplantation.

RESULTS

The overall failure rate was 20.0% (18 of 90 ears); of the failures, 15 of 18 (83.3%) were hard device failures, and 3 of 18 (16.7%) were medical or surgical failures. All hard device failures were confirmed with integrity testing as performed by the company. The average time to integrity testing was 38.0 months. Of the hard failures, 14 of 15 had successful initial activation and benefit. Lack of expected progress was seen in 7 of 15 and a sudden decline in function in 8 of 15. Electrodes 9 to 16 were most often defunct. Significant drops in speech perception were often seen in device failure cases. Three medical/surgical failures were explanted; one had migration of the receiver/stimulator causing discomfort, and the other two had electrode migration after partial insertion. Of the reimplanted patients, 11 of 12 are deriving benefit from their new devices.

CONCLUSIONS

The rate of device failure for the cochlear implants of interest is significantly higher in our series than reported in the initial FDA voluntary field corrective action publication.

Clinical profile and management of revision cochlear implant surgeries

OBJECTIVES

To discuss our experience with managing cochlear implant cases that required revision surgery.

METHODS

A retrospective case series study including data from 922 cochlear implant patients at an academic tertiary center was evaluated retrospectively. All patients who underwent revision cochlear implant (CI) surgery between January 2011 and July 2017 were included. The following data were collected: patient demographic data, details on the first implant, reasons for the revision, duration from initial implantation to revision, type of device, and management.

RESULTS

Out of 922 CI patients, 37 (4%) underwent revision surgery, comprising 33 children and 4 adults. The most common reason for revision surgery, at 28/37 cases (75.6%), was device failure. Surgical and medical aetiologies were responsible for 9/37 (24.3%) revisions. The mean duration from the initial implantation to the revision surgery was 29 months.

CONCLUSION

Revision CI surgery is not uncommon after initial implantation. Cochlear implant programs must implement long-term follow-up processes for CI users. Whenever a patient's rehabilitated performance regresses, the cause should be investigated to determine whether subsequent reimplantation is necessary.

Cochlear Implant Reliability: On the Reporting of Rates of Revision Surgery

The aim of this study was to determine the magnitude of the risks associated with cochlear implantation. Results from a pool of thirty clinical studies involving cochlear implantation in over 6300 children were obtained from an internet search. The relevant data were transformed to a common time base (patient time) to allow an evaluation of events following implantation. The main outcome measure was cumulative survival probability for all-cause revision surgery. Over 10 years this was estimated to be 0.71. Thus, at 10 years post-implantation close to 30% of children with unilateral implants will have undergone revision surgery. This figure is considerably greater than that commonly reported for overall revision rates and illustrates the importance of interpreting results with respect to the relevant time frame. When non and low-use is incorporated into the analysis the above figure rises to about 37% of children affected. The findings raise concerns about the information provided to both individuals and regulatory bodies regarding the risks associated with cochlear implantation. The consequences for bilateral implantation are apparent. Our recommendations are i) a full disclosure to parents and children of the true magnitude of the risks and ii) for a body with significant expertise in reliability and systems engineering, and no conflicts of interest, to play a major role in the regulatory management of this service.

When to replace legacy cochlear implants for technological upgrades: Indications and outcomes

OBJECTIVE

To determine indications, surgical efficacy, and audiologic outcomes of replacing Advanced Bionics Clarion C1.2 internal devices (Advanced Bionics, LLC, Valencia, CA) as a means of technology upgrade.

STUDY DESIGN

Retrospective review, case series.

METHODS

Ten patients were initially implanted as a child (mean age = 3.87 years) and underwent cochlear implant reimplantation (CIR) with current Advanced Bionics internal device as a young adult (mean duration of implant use = 15.66 years). Demographic data and pre- and post-CIR speech perception scores were collected.

RESULTS

Technology upgrade was the primary (9) or secondary (1) motivation for CIR. No surgical complications were noted, and full insertion was obtained in nine cases. Intraoperative impedance levels and neural response imaging measures were within normal limits for eight patients. At most recent post-CIR follow-up evaluation, all patients (100%) performed within or better than the 95% confidence interval of their pre-CIR word and sentence recognition scores; and 55.6%, 50.0%, and 50.0% of patients performed above the 95% confidence interval of their pre-CIR scores for the CNC words, sentences in quiet, and sentences in noise, respectively.

CONCLUSION

Post-CIR audiological benefit was stable or improved compared to pre-CIR results in all categories by 3 months after reactivation. Given these results, patients who are unable to use the most current external processors due to incompatibility with a legacy internal device could consider reimplanation to optimize their overall performance with a cochlear implant.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:748-753, 2019.

Comparisons of Auditory Performance and Speech Intelligibility after Cochlear Implant Reimplantation in Mandarin-Speaking Users

Objectives. We evaluated the causes, hearing, and speech performance before and after cochlear implant reimplantation in Mandarin-speaking users. Methods. In total, 589 patients who underwent cochlear implantation in our medical center between 1999 and 2014 were reviewed retrospectively. Data related to demographics, etiologies, implant-related information, complications, and hearing and speech performance were collected. Results. In total, 22 (3.74%) cases were found to have major complications. Infection (n = 12) and hard failure of the device (n = 8) were the most common major complications. Among them, 13 were reimplanted in our hospital. The mean scores of the Categorical Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) obtained before and after reimplantation were 5.5 versus 5.8 and 3.7 versus 4.3, respectively. The SIR score after reimplantation was significantly better than preoperation. Conclusions. Cochlear implantation is a safe procedure with low rates of postsurgical revisions and device failures. The Mandarin-speaking patients in this study who received reimplantation had restored auditory performance and speech intelligibility after surgery. Device soft failure was rare in our series, calling attention to Mandarin-speaking CI users requiring revision of their implants due to undesirable symptoms or decreasing performance of uncertain cause.