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

Abstract

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. Metaanalysis estimated an overall rate of postoperative meningitis of 0.07% (95% confidence interval [CIs], 0.03%-0.1%; I 2 = 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.

An overview of risk factors, management and prevention of cochlear implant infections

“…Importantly, meningitis has been observed to occur most commonly following acute OM of the ipsilateral ear [6]. Individuals with an inner ear malformation [26,27 ▪▪ ], previous meningitis or cerebrospinal fluid (CSF) leak [4 ▪ ,9]. are additionally at baseline increased risk of meningitis, aside from the risk associated with the CI surgery itself.…”

“…However, there is data supporting a decrease in pneumococcal colonization in vaccinated CI recipients compared to healthy unvaccinated controls and animal models that suggest prevention of CI associated meningitis with pneumococcal vaccination [47–49]. In 2022, the Centers for Disease Control and Prevention revised their vaccination guidelines incorporating the administration of the conjugate pneumococcal vaccine (Pneumovax23) for unvaccinated adults undergoing cochlear implantation [13 ▪▪ ]. In the United Kingdom and Australia, those undergoing cochlear implantation are recommended an additional dose of Prevenar13 and Pneumovax23 [13 ▪▪ ,50].…”

“…In 2022, the Centers for Disease Control and Prevention revised their vaccination guidelines incorporating the administration of the conjugate pneumococcal vaccine (Pneumovax23) for unvaccinated adults undergoing cochlear implantation [13 ▪▪ ]. In the United Kingdom and Australia, those undergoing cochlear implantation are recommended an additional dose of Prevenar13 and Pneumovax23 [13 ▪▪ ,50]. A meta-analysis recently showed suboptimal vaccine uptake in CI recipients with only 62% of children and 15% of adults vaccinated with Prevenar13 [51 ▪ ].…”

“…This led to a number of papers further describing meningitis following cochlear implantation and a recall on positioner use for CI [9–12]. A recent systematic review in 2023 demonstrated a considerable reduction in meningitis (0.05–0.1%) in more contemporary CI cohorts following this [13 ▪▪ ].…”