Seven-Year Revision Rates for Cochlear Implants in Pediatric and Adult Populations of an Integrated Healthcare System.

OBJECTIVE: We assessed three cochlear implant (CI) suppliers: Advanced Bionics, Cochlear Limited, and MED-EL, for implant revision requiring reoperation after CI placement. STUDY DESIGN: Retrospective cohort study of integrated-health-system database between 2010 and 2021. Separate models were created for pediatric (age <18) and adult (age ≥18) cohorts. PATIENTS: Pediatric (age <18) and adult (age ≥18) patients undergoing cochlear implantation within our integrated healthcare system. MAIN OUTCOME MEASURE: Revision after CI placement. Cox proportional hazard regression was used to evaluate revision risk and adjust for confounding factors. Hazard ratios (HRs) and 95% confidence intervals (CIs) are presented. RESULTS: A total of 2,347 patients underwent a primary CI placement, and Cochlear Limited was most implanted (51.5%), followed by Advanced Bionics (35.2%) and MED-EL (13.3%). In the pediatric cohort, the 7-year crude revision rate was 10.9% for Advanced Bionics and 4.8% for Cochlear Limited, whereas MED-EL had insufficient cases. In adults, the rates were 9.1%, 4.5%, and 3.3% for Advanced Bionics, MED-EL, and Cochlear Limited, respectively. After 2 years of postoperative follow-up, Advanced Bionics had a significantly higher revision risk (HR = 8.25, 95% CI = 2.91-23.46); MED-EL had no difference (HR = 2.07, 95% CI = 0.46-9.25). CONCLUSION: We found an increased revision risk after 2 years of follow-up for adults with Advanced Bionics CI devices. Although we found no statistical difference between manufacturers in the pediatric cohort, after 2 years of follow-up, there were increasing trends in the revision probability for Advanced Bionics. Further research may determine whether patients are better suited for some CI devices.

Incidence and indications for revision cochlear implant surgery in adults and children.

OBJECTIVES/HYPOTHESIS: To identify the incidence of and common causes for cochlear implant revision. STUDY DESIGN: Retrospective case series. METHODS: Operative records were reviewed for all cases of revision cochlear implantation from 1992 to 2006. The causes for reimplantation were classified as hard device failure, soft device failure, exposure/infection, receiver/stimulator migration, and electrode migration. Manufacturers' failure analysis of explanted devices was likewise determined. RESULTS: Eight hundred and six cochlear implants were performed during the study period including 44 (5.5%) revision procedures. The revision rate was 7.3% for children and 3.8% for adults and reached statistical significant difference. The most common reasons for revision were device failure (78%; 55% hard failure, 23% soft failure) followed by electrode migration (9%) and receiver/stimulator migration (7%). Manufacturers' analysis of failed devices revealed loss of hermetic seal and cracked cases to be the most common causes of failure. Bench analysis of 5/10 explanted devices that were soft failures demonstrated identifiable device defects. CONCLUSIONS: Revision cochlear implant surgery is an infrequent occurrence. Its incidence appears to be higher in children than in adults, although in this series does not appear to be due to increased wound complications, infections, or trauma. Explanted implants that have soft failure as the etiology may have demonstrable defects on bench testing.

Cochlear implantation in organ transplantation.

OBJECTIVES/HYPOTHESIS: Compared to immunocompetent patients, organ transplant recipients receiving immunosuppressant medications may experience higher rates of postoperative complications. This study was designed to retrospectively review the outcomes of cochlear implantation among organ transplant patients. STUDY DESIGN: Retrospective case series. METHODS: Five organ transplant patients received seven cochlear implantations at the University of Miami Ear Institute from January 1, 1992, until August 31, 2005. Inpatient and outpatient records were analyzed to identify healing problems, wound infections, and speech recognition after implantation. RESULTS: There were no healing problems, wound infections, or other complications noted among cochlear implant recipients who had also received organ transplantation. Open-set sentence discrimination as measured by the Hearing in Noise Test (HINT), City University of New York (CUNY) test, and/or Central Institute for the Deaf (CID) tests ranged from 46% to 89%. Open-set word recognition as measured by the Consonant Nucleus Consonant (CNC) or the Northwestern University number 6 (NU-6) test ranged from 26% to 64%. CONCLUSIONS: This series suggests that cochlear implantation can be safe and effective for solid organ transplant recipients on immunosuppressants, with discrimination performance within the expected ranges for cochlear implant patients

Electrode migration after cochlear implantation.

OBJECTIVE: To review the occurrence of electrode migration after cochlear implantation. STUDY DESIGN: Review of public database and retrospective case series. SETTING: Tertiary academic referral center, ambulatory. PATIENTS: Retrospective review of electrode migration reported in association with the US Food and Drug Administration Manufacturer and User Facility Device Experience database and a single-institution case series between 1996 and 2006. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURE: Occurrence of electrode migration. RESULTS: During the period 1996 to 2006, 151 reports of electrode migration were filed in the Manufacturer and User Facility Device Experience database. The most common association with migration was cochlear ossification, although 127 of 151 cases had no known association. During an equivalent period, 637 cochlear implant (CI) procedures were performed at the University of Miami. Of 580 primary CI operations, 2 cases of electrode migration were identified, both associated with reossification of a cochlea that was fully ossified at the first procedure. CONCLUSION: Electrode migration is an underrecognized complication of CI surgery and may be associated with cochlear ossification. Electrode stabilization techniques may reduce the incidence of CI electrode migration in nonossified or incompletely ossified cases.

Performance after cochlear implantation in DFNB1 patients.

OBJECTIVE: To evaluate the speech perception and language development with cochlear implants (CI) of DFNB1 children in comparison with non-DFNB1 deaf children. STUDY DESIGN: Retrospective case series. SETTING: Academic tertiary center. RESULTS: Thirty-one congenitally deafened children, screened for GJB2 allele variants, were followed for an average 32 months after CI. With the use of age-appropriate testing, 75% of DFNB1 and 53% of non-DFNB1 children achieved open set word recognition (speech perception category [SPC] level 6). Multivariate analysis showed that SPC was primarily dependent on duration of CI use, but not on the cause of hearing loss. In Reynell language tests, DFNB1 children showed more consistent and quicker gains than non-DFNB1 children. CONCLUSION: Although children with CI with DFNB1 show faster gains in Reynell scores, duration of CI use appears to have a greater effect on speech perception than DFNB1 status. SIGNIFICANCE: Identification of DFNB1 children is useful in counseling of CI outcomes.

Conservation of residual acoustic hearing after cochlear implantation.

OBJECTIVE: This study was designed to test the hypothesis that partial hearing conservation is attainable after cochlear implantation with a long perimodiolar electrode. Surgical strategies for hearing conservation during cochlear implantation are described. STUDY DESIGN: Prospective, single-subject, repeated-measures design. SETTING: Academic tertiary care center. PATIENTS: Twenty-eight severely to profoundly hearing-impaired adult cochlear implant recipients who had some measurable hearing preoperatively. INTERVENTION: Cochlear implantation using Nucleus Freedom Contour Advance electrode. MAIN OUTCOME MEASURES: Preimplant and postimplant pure-tone thresholds and speech recognition scores were obtained to determine the incidence and degree of conserved hearing at a mean interval of 9 (+/-3.9) months. RESULTS: Thirty-two percent of subjects experienced complete conservation of hearing (0- to 10-dB loss), and 57% experienced partial conservation of hearing (>11 dB) after implantation. However, open-set speech recognition was partially conserved in only one subject. Cochlear implant performance was not better in patients with conservation of residual hearing. CONCLUSION: Conservation of pure-tone hearing was possible in 89% of implanted patients; however, residual speech perception was not conserved with this long perimodiolar electrode. A ceiling effect tends to inflate the prevalence of hearing conservation in implantation studies of severely to profoundly hearing-impaired patients.

The effect of organ of corti loss on ganglion cell survival in humans.

HYPOTHESIS: Severe spiral ganglion cell loss does not necessarily follow loss of hair cells or supporting cells in humans. BACKGROUND: Despite some publications to the contrary, statements that loss of hair cells and/or supporting cells of the organ of Corti results in a severe loss of spiral ganglion cells in humans still appear in the literature, especially in respect to cochlear implants. This assumption is apparently based on studies in animals or cell culture and not from studies of human temporal bones. METHODS: Morphological analysis of archival temporal bones with microscopic and statistical analysis of ganglion cell, hair cell, and supporting cell populations was performed in 33 ears with total hearing losses of varying causes and durations of deafness. None of the ears had remaining hair cells. Six ears had had cochlear implants. RESULTS: Ganglion cell counts ranging from 2,889 to 34,299 and the corresponding percentage of remaining ganglion cells based on age-normative data were not significantly related to the duration of hearing loss (r = -0.13 and 0.02, respectively, p > 0.05) or to remaining supporting cell populations (r's from 0.15 to 0.27, p > 0.05). More than half of ears (51.5%) had ganglion cell counts within two standard deviations of age-normative means. Mean ganglion cell counts and percentage of remaining ganglion cells of ears with surviving peripheral processes (dendrites) did not differ significantly from those of ears with no peripheral processes. CONCLUSION: The loss of hair and supporting cells in the organ of Corti in humans does not necessarily result in as significant a loss of spiral ganglion cells as has been reported animals. In fact, our results suggest that ganglion cell loss may be a primary concomitant loss due to the disease process.

Cochlear implants.

Cochlear implants are cost-effective auditory prostheses that safely provide a high-quality sensation of hearing to adults who are severely or profoundly deaf. In the past 5 years, progress has been made in hardware and software design, candidate selection, surgical techniques, device programming, education and rehabilitation,and, most importantly, outcomes. Cochlear implantation in the elderly is well tolerated and provides marked improvement in auditory performance and psychosocial functioning.

MRI evaluation of neurofibromatosis 2 patients: a standardized approach for accuracy in interpretation.

OBJECTIVE: To determine the level of agreement between local radiologists' and an experienced neuroradiologist's measurements of vestibular schwannomas. STUDY DESIGN: Prospective study with uniform magnetic resonance acquisition protocol parameters and reporting instructions across 30 magnetic resonance imaging facilities worldwide. SETTING: Multicenter natural history study of neurofibromatosis Type 2. SUBJECTS: One hundred fifteen magnetic resonance imaging examinations of 57 neurofibromatosis Type 2 patients older than 5 years of age. INTERVENTIONS: Thin-slice, postcontrast cranial magnetic resonance imaging. MAIN OUTCOME MEASURES: Spearman's rho interobserver association coefficient of vestibular schwannoma linear measurements. RESULTS: The local and experienced radiologist measurements and identification of tumors agreement was fair (kappa = 0.77). Discordant interpretations were adjudicated by another experienced neuroradiologist. CONCLUSION: The least interobserver variability was found in measurements of thin-slice postcontrast magnetic resonance imaging scans obtained at neurofibromatosis Type 2 centers in patients without previous operations and moderately sized tumors. If the schwannoma was difficult to assess, because of magnetic resonance imaging acquisition protocol, postoperative changes, or tumors smaller than 5 mm in greatest diameter, the neuroradiologist provided a more thorough assessment. The authors suggest uniform reporting criteria for vestibular schwannoma assessments to ensure clinically relevant information is communicated regarding vestibular schwannoma size.