Cochlear Implantation in Organ Transplantation

Biomarkers from subcutaneous engineered tissues predict acute rejection of organ allografts

Invasive graft biopsies assess the efficacy of immunosuppression through lagging indicators of transplant rejection. We report on a microporous scaffold implant as a minimally invasive immunological niche to assay rejection before graft injury. Adoptive transfer of T cells into Rag2-/- mice with mismatched allografts induced acute cellular allograft rejection (ACAR), with subsequent validation in wild-type animals. Following murine heart or skin transplantation, scaffold implants accumulate predominantly innate immune cells. The scaffold enables frequent biopsy, and gene expression analyses identified biomarkers of ACAR before clinical signs of graft injury. This gene signature distinguishes ACAR and immunodeficient respiratory infection before injury onset, indicating the specificity of the biomarkers to differentiate ACAR from other inflammatory insult. Overall, this implantable scaffold enables remote evaluation of the early risk of rejection, which could potentially be used to reduce the frequency of routine graft biopsy, reduce toxicities by personalizing immunosuppression, and prolong transplant life.

Cochlear implantation after solid organ transplantation: long term results and review of the literature

OBJECTIVE

To analyze rate and type of complications in cochlear implant (CI) recipients receiving immunosuppressive therapy following solid organ transplant (SOT).

STUDY DESIGN

Retrospective case series. English language literature review.

SETTING

Tertiary referral center.

INTERVENTION

Cochlear implantation surgery following solid organ transplantation (SOT) and immunosuppressive therapy.

METHODS

Data of patients who received CI after SOT and with at least one year of follow up were reviewed. Main outcome measures were the rate and type of complications, classified as major (requiring a second surgical procedure) and minor (requiring medical therapy). A search was performed in PubMed database on January 2019 using the keywords: organ transplant; cochlear implant, complications, deafness, solid organ transplant, immunosuppressive therapy. Only studies reporting on patients who have been implanted after the transplant procedure and with a follow up period of at least 1 year were considered. Final analysis was performed on pooled data.

RESULTS

Four patients received CI surgery following SOT. Age at treatment ranged from 40 to 47 years (mean 44.25 years). Follow-up after implantation averaged 5.25 years (range 1-10 years), without complications. Review of the available literature on the subject yielded seven papers; a total of 26 procedures in 22 patients satisfied inclusion criteria. Pooled data from the present series and from the literature were analyzed; the global rate of complications was 16.6%, with 10% major (3 of 30 procedures) and 6.6% minor (2 of 30 procedures). The three reported cases of major complications appear unrelated to SOT. Major complications were found in one case over 16 procedures in pediatric patients (6.2%), while in adults the percentage raised to 14.3% (2/14 procedures).

CONCLUSIONS

Cochlear implantation is a safe and effective intervention, even during immunosuppressive therapy after organ transplantation.

Cochlear Implantation in Organ Transplant Recipients

OBJECTIVE

Immunosuppressed individuals who have undergone organ transplants, especially children, pose particular challenges in terms of treatment. The aim of this study was to analyze the postoperative complication rate of organ transplant recipients who have also received a cochlear implant (CI).

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

INTERVENTION

The case series includes 13 kidney, liver, lung, and heart transplant patients. Age at treatment ranged from 2 to 71 years, with a total of 17 CIs.

MAIN OUTCOME MEASURES

Postoperative complications were classified into major and minor, early (within 3 mo postoperatively) and late (>3 mo postoperatively). The results were compared with those for 13 1:1 matched pairs obtained and from our database and a healthy patient collective from our department.

RESULTS

The global postoperative complication rate was 29.4%. The proportion of patients suffering major complications was 17.6%, with 17.6% having minor complications. Complications that occurred early accounted for 13.3%, and late for 26.7%. No adults, and 33.0% of children, showed any complications after cochlear implantation. The global complication rate (29.4%) was significantly increased compared with the matched pairs (0%, p = 0.013) and department data (13.8%, p = 0.006; Cramers v = 0.102).

CONCLUSION

This study demonstrates that organ transplant recipients, and especially children, are at increased risk of postoperative complications after cochlear implantation in comparison with healthy CI recipients.

Cochlear implantation of solid organ transplant patients receiving immunosuppressive therapy

OBJECTIVE

To evaluate the incidence of infectious complications and healing problems in cochlear implant (CI) patients receiving immunosuppressive therapy following solid organ transplant.

STUDY DESIGN

IRB-approved retrospective chart review of implanted patients.

SETTING

Tertiary care children's hospital.

METHODS

Seven patients of the more than 1000 implanted during the time period between 1991 and 2014 underwent cochlear implantation while on immunosuppressive therapy after having received a solid organ transplant. Their charts were reviewed for demographic and medical information pre- and post-implantation. The 4 males and 3 females ranged in age at CI from 2.4 to 18.8 years, with a mean of 9.0 years. Postimplant follow-up averaged 3.9 years (range: 0.1-13.1). Main outcome measures were occurrence of wound healing, infectious complications, whether open-set word recognition was achieved, and communication mode(s).

RESULTS

No wound infections or delayed healing, mastoiditis, or bacterial meningitis occurred after cochlear implantation. All seven patients had received at least one pneumococcal vaccination prior to implantation. Five of 6 (83%) developed open-set speech perception, of whom 4 (67%) use only oral communication.

CONCLUSION

In our series of patients receiving immunosuppressive therapy following solid organ transplantation, none developed wound healing or infectious complications after cochlear implantation. History of solid organ transplantation alone should not be a contraindication to cochlear implant candidacy which would deprive the child of the potential benefits of hearing, including language development.

Cochlear implantation in a patient with combined renal and liver transplantation

OBJECTIVE AND IMPORTANCE

Patients who have undergone solid organ transplantation and continuing immunosuppressant medication are at a higher risk of wound problems and infections following cochlear implantation. This risk is theoretically even further increased in multi-organ transplant recipients due to the increased doses of immunosuppressive medications that these patients are administered.

CLINICAL PRESENTATION AND INTERVENTION

Here, we present the first reported case of successful cochlear implantation in a patient who had previously undergone successful combined liver and kidney transplant. She had no significant complications from the surgery and had good audiological outcomes 3 months post-operatively.

CONCLUSION

As we continue our advances in the use of cochlear implant technology, our report adds to the growing evidence of its benefits in transplant recipients. However, there are important pre- and peri-operative considerations in this group of patients which can improve safety and outcome.

Prevention and management of cochlear implant infections

Understanding the issues of infection related to an implantable medical device is crucial to all cochlear implant teams. Furthermore, given the risk of central nervous system complications and the relatively high quantity of underlying resource investment associated with cochlear implantation, the stakes of infection are high. The optimal strategies to prevent and manage such infections are still evolving as good-quality prospective data to guide such management decisions are not yet abundant within the medical literature and many recommendations are based on retrospective reviews or anecdotal evidence. We will outline a general strategy to deal with cochlear implant-related infection based on both the authors' experience and the published literature.

Cochlear implantation after renal transplantation

OBJECTIVE

Cochlear implantation after renal transplantation is uncommon and poses unique challenges that have only recently been described in the medical literature. This work reports our experience with cochlear implantation in patients who have undergone renal transplantation.

STUDY DESIGN

A retrospective review was performed.

SETTING

This study was performed in a tertiary academic medical center.

PATIENTS

Two patients were identified as having undergone cochlear implantation after renal transplantation.

INTERVENTIONS

Uneventful unilateral cochlear implantations were performed.

MAIN OUTCOME MEASURES

Postoperative complications to include wound infection or dehiscence were reported as well as audiometric data.

RESULTS

Cochlear implantation was completed uneventfully in both patients without postoperative complications. One patient expired two years after the procedure as a result of multiple comorbidities. Both patients achieved successful use of their device.

CONCLUSIONS

This study adds to the growing evidence that successful cochlear implantation can be achieved in appropriately selected renal transplant patients. Decision making should rely on surgical candidacy as well as assessment of surgical risk in collaboration with the transplant service.