Cochlear Implant Infections and Outcomes: Experience From a Single Large Center

Cochlear Implant Infections

Cochlear implants (CIs) are associated with a range of infections. These infections present unique considerations because of their position relative to the respiratory tract and the central nervous system, as well as the propensity for biofilms to form on CIs. This article reviews infections related to CIs, including otitis media, mastoiditis, meningitis, and deep CI infection. High-quality evidence on the prevention and management of CI infections is lacking; however, best practices regarding prevention and management are provided.

[Standardized risk-based antibiotic prophylaxis and adhesive film dressing for the prevention of wound infection following cochlear implantation]

BACKGROUND

There is no consensus in the pertinent literature regarding the optimal antibiotic prophylaxis (AP) for cochlear implantation (CI). This study evaluates the implementation of standardized risk-based AP combined with application of an adhesive film dressing.

MATERIALS AND METHODS

All CI cases since September 2019 were retrospectively reviewed for postoperative wound complications. While all patients received preoperative AP with ceftriaxone, postoperative AP after CI in patients older than 7 years was no longer routinely performed in our clinic. Exceptions were made according to predefined criteria for an increased risk of infection. The wound was covered with a transparent adhesive polyurethane film.

RESULTS

In 72% of the 219 cases, we did not perform postoperative AP. The overall wound complication rate was 2.7% (in the groups with and without postoperative AP, 4.9% and 1.9%, respectively). Wound infection did not occur in any of the patients without postoperative AP older than 70 years (n = 32), with controlled diabetes mellitus (n = 19), or with reimplantation due to technical defect (n = 19). The film did not need to be changed until the suture material was removed.

CONCLUSION

Standardized risk-based AP can avoid prolonged administration of antibiotics in selected patients. The film dressing permits continual examination and sufficient wound protection.

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

PURPOSE OF REVIEW

With cochlear implantation becoming increasingly performed worldwide, an understanding of the risk factors, preventive measures, and management of cochlear implant (CI) infection remains important given the significant morbidity and cost it conveys.

RECENT FINDINGS

At the turn of the 21st century there was a decrease in rates of CI infection, particularly meningitis, following the discontinuation of positioner use for CI. However, in more recent years rates of CI infection have remained largely static. Recently, studies evaluating preventive measures such as pneumococcal vaccination, S. aureus decolonization and surgical antibiotic prophylaxis have emerged in the literature.

SUMMARY

Prompt recognition of CI infection and appropriate investigation and management are key, however at present treatment is largely informed by cohort and case-control studies and expert opinion. Preventive measures including pneumococcal vaccination, S. aureus decolonization and preoperative antibiotic prophylaxis play a role in reducing rates of CI infection. However, there remains a need for well designed clinical trials to provide higher level evidence to better guide preventive measures for, and management decisions of, CI infections in the future.

Fluorescence in situ hybridization and microbial community profiling analysis of explanted cochlear implants

BACKGROUND

Cochlear implant (CI) infections affect a small, but significant number of patients. Unremitting infections can lead to explantation. Fluorescence in situ hybridization (FISH) and microbial community profiling (MCP) are methods of studying microbial environments of explanted devices that can provide information to reduce morbidity and costs of infected CIs.

AIMS/OBJECTIVES

To describe the results and clinical significance of bacterial analyses conducted on explanted CIs.

MATERIAL AND METHODS

Between 2013 and 2017, 12 explanted devices underwent microbiological analysis in addition to the manufacturer's device failure analysis. Patients' clinical history, infection status and outcome were reviewed and correlated with microbial analysis results.

RESULTS

From 2013 to 2017, 12 Cochlear™ devices from 11 patients underwent additional MCP or FISH analysis. Five devices were explanted due to suspected implant associated infection, and seven were explanted for other reasons. FISH analysis revealed biofilm presence on all infected devices, only partial correlation of cultures with biofilm composition and confirmation that biofilm formation occurs preferentially at particular device interfaces and geometries. MCP analysis presented challenges in data analysis inherent to its technique but correlated with cultures of infected devices and suggested a diverse microbial composition of explanted devices.

CONCLUSIONS AND SIGNIFICANCE

Microbial analysis of explanted devices can aid in further elucidating treatment approaches to infected CIs.

Pain at the Cochlear Implant Site Requiring Device Removal in Pediatric Patients

OBJECTIVES

Idiopathic pain at the cochlear implant (CI) site outside of the immediate postoperative period is an uncommon occurrence but may necessitate device explantation. Our objective was to describe the clinical course for pediatric patients with CI site pain who ultimately required device explantation.

STUDY DESIGN

Retrospective chart review.

METHODS

We performed a retrospective database review of CIs performed at a tertiary referral center for pediatric cochlear implantation. We specifically evaluated pediatric patients who presented with pain at or near the CI device site and ultimately required explantation.

RESULTS

Fifteen patients (16 CIs) had pain at or near the CI site requiring device explantation. Cultures taken during site exploration or device explantation identified bacteria in 86% and 81% of procedures, respectively. Propionibacterium acnes and Staphylococcus non-aureus were the most commonly identified organisms.

CONCLUSIONS

The majority of patients with idiopathic pain in this cohort ultimately requiring CI explantation had chronic bacterial colonization.

LEVEL OF EVIDENCE

Level 4 (Case series) Laryngoscope, 2022.

Impact of preoperative antibiotic use in preventing complications of cochlear implantation surgery

OBJECTIVE

To examine the impact of preoperative antibiotic prophylaxis on the occurrence of postoperative complications.

MATERIALS AND METHODS

Data of 491 patients undergoing cochlear implantation were included in a non-randomized retrospective comparative cohort study. Demographic data, cochlear implant and surgical details, use of preoperative antibiotics and occurrence of postoperative complications were analyzed using a binary logistic regression model.

RESULTS

There were 317 patients (64.56%) who did not receive preoperative antibiotic prophylaxis and 174 (35.44%) patients who received preoperative antibiotic prophylaxis with ceftriaxone. The overall rate of complications requiring surgical treatment was 2.85%. Younger patient age was identified as a positive predictive factor for administering preoperative antibiotic prophylaxis (p<0.001, OR 1.05 CI 95% 1.0124-1.0826). No difference in complication rate was observed between the two groups. No correlation between sex, age, manufacturer, surgeon and postoperative complications were noted (p=0.45).

CONCLUSION

There is insufficient evidence to inform decision making regarding preoperative intravenous ceftriaxone use for prevention of infection after cochlear implantation surgery, with data failing to show that administration of preoperative antibiotics leads to a decrease in complication rate. Considering a very low overall complication rate, with few complications related to infection, routine use of preoperative antibiotic prophylaxis should be analyzed further.