Safety of Cochlear Implantation in Children 12 Months or Younger: Systematic Review and Meta-analysis

National Trends in Cochlear Implantation Across the Department of the Defense: A Case for Inclusion as a General Otolaryngology Core Competency

OBJECTIVE

With ongoing national expansions in cochlear implantation (CI) candidacy criteria, more patients qualify for CI today than ever before. Among US veterans and military service members, the prevalence of qualifying degrees of hearing loss secondary to occupational noise exposure exceeds the general population. The primary aim of the current work was to evaluate CI trends across the military health system.

STUDY DESIGN

Database review.

SETTING

Military and civilian practices.

PATIENTS

Department of Defense (DoD) beneficiaries who underwent CI.

MAIN OUTCOME MEASURES

CI rates between 2010 and 2019.

RESULTS

A total of 3,573 cochlear implant operations were performed among DoD beneficiaries from 2010 to 2019. A majority of patients (55%) were older than 64 years, with the next most commonly implanted age group being 0 to 4 years of age (14%). From 2010 to 2019, annual CI increased at a rate of 7.9% per year for all implantation over the study period ( r = 0.97, p < 0.0001); there was a statistically significant difference of this rate compared with tympanoplasty, which was used as a reference procedure (rate, -1.9%; p = 0.03). This trend was similar for beneficiaries implanted both in military (11.9% per year, r = 0.77, p = 0.009) and civilian facilities (7.7% per year, r = 0.96, p < 0.0001); there was no statistically significant difference between the annual growth rates of these groups ( p = 0.68).

CONCLUSIONS

Although the number of devices implanted is rapidly increasing among DoD beneficiaries, reported national utilization rates remain low. This disparity likely exists in the general public, considering the aging demographic in the West and continual expansions in US Federal Drug Administration labeling. These data suggest that widespread expansion of the procedure to general otolaryngology practices will be required to meet current and future demands for CI. For this reason, CI should be considered for "key indicator" designation among residency training programs.

The Risk of Meningitis After Cochlear Implantation: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to estimate the rate of postoperative meningitis (both immediate and long-term) in patients following cochlear implants (CIs). It aims to do so through a systematic review and meta-analysis of published studies tracking complications after CIs.

DATA SOURCES

MEDLINE, Embase, and Cochrane Library.

REVIEW METHODS

This review was performed in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies tracking complications following CIs in patients were included. Exclusion criteria included non-English language studies and case series reporting <10 patients. Bias risk was evaluated using the Newcastle-Ottawa Scale. Meta-analysis was performed through DerSimonian and Laird random-effects models.

RESULTS

A total of 116/1931 studies met the inclusion criteria and were included in the meta-analysis. Overall, there were 112 cases of meningitis in 58,940 patients after CIs. Meta-analysis estimated an overall rate of postoperative meningitis of 0.07% (95% confidence interval [CIs], 0.03%-0.1%; I2  = 55%). Subgroup meta-analysis showed this rate had 95% CIs crossing 0% in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, those with postoperative acute otitis media (AOM), and those implanted less than 5 years.

CONCLUSION

Meningitis is a rare complication following CIs. Our estimated rates of meningitis after CIs appear lower than prior estimates based on epidemiological studies in the early 2000s. However, the rate still appears higher than the baseline rate in the general population. The risk was very low in implanted patients who received the pneumococcal vaccine, antibiotic prophylaxis, received unilateral or bilateral implantations, developed AOM, those implanted with a round window or cochleostomy techniques, and those under 5 years.

Auditory Outcomes in Children Who Undergo Cochlear Implantation Before 12 Months of Age: A Systematic Review

OBJECTIVE

To systematically review the literature to determine auditory outcomes of cochlear implantation in children ≤12 months old.

DATA SOURCE

PubMed, EMBASE, Medline, CINAHL, Cochrane, Scopus, and Web of Science databases were searched from inception to 9/1/2021 using PRISMA guidelines.

REVIEW METHODS

Studies analyzing auditory outcomes after cochlear implantation (CI) in children ≤12 months of age were included. Non-English studies and case reports were excluded. Outcome measures included functional and objective auditory results. Two independent reviewers evaluated each abstract and article. Heterogeneity and bias across studies were evaluated.

RESULTS

Of 305 articles identified, 17 met inclusion criteria. There were 642 children ages 2 to 12 months at CI. The most common etiologies of hearing loss were congenital CMV, meningitis, idiopathic hearing loss, and GJB2 mutations and other genetic causes. All studies concluded that early CI was safe. Overall, outcomes improved following early CI: IT-MAIS (9 studies), LittlEARS (4 studies), PTA (3 studies), CAP (3 studies), GASP (3 studies), and LNT (3 studies). Nine studies compared outcomes to an older implantation group (>12 months); of these (n = 450 early CI, n = 1189 late CI), 8 studies showed earlier CI achieved comparable or better auditory outcomes than later implantation, whereas 1 study (n = 120) concluded no differences in speech perception improvement.

CONCLUSION

Auditory outcomes were overall improved in children ≤12 months old undergoing CI. Studies that compared early to late CI demonstrated similar or better auditory outcomes in early implantation group. Given the comparable safety profile and critical time period of speech and language acquisition, earlier CI should be considered for infants with hearing loss.

Younger Age at Cochlear Implant Activation Results in Improved Auditory Skill Development for Children With Congenital Deafness

PURPOSE

The U.S. Food and Drug Administration indications for cochlear implantation in children is currently 9 months of age and older for children with bilateral profound sensorineural hearing loss (SNHL). Studies have shown that earlier activation of a cochlear implant (CI) can lead to better spoken language outcomes. As auditory skills are a precursor to the development of spoken language, this study was developed to investigate the influence of age at CI activation on auditory skill acquisition in young children. A secondary aim was to describe the auditory skills of children implanted prior to 9 months of age as compared to children with older ages of activation.

METHOD

Functional Listening Index (FLI) scores obtained during routine clinical visits were reviewed for 78 pediatric CI recipients with congenital bilateral profound hearing loss who were activated before 2 years of age. A linear mixed-effects model assessed the effect of age at CI activation on cumulative FLI scores over time.

RESULTS

There was a significant interaction between age at activation and chronological age at the time of evaluation, indicating that children with earlier access to sound achieved a greater number of auditory skills than those with later CI activations when measured at the same chronological age. Children activated before the age of 9 months approximated scores expected of children with typical hearing, whereas children activated between 9 and 24 months of age did not.

CONCLUSIONS

Younger age at CI activation is associated with increased auditory skills over time. Children who undergo cochlear implantation and CI activation before 9 months achieve more auditory skills by 4 years of age than children who are activated at later ages. These data suggest that reducing the approved age at cochlear implantation for children with congenital bilateral profound SNHL may support optimal auditory skill acquisition.