Cochlear Reimplantation after Surgery for Electric-Acoustic Stimulation

Abstract

Background/Aims: Combined electric-acoustic stimulation (EAS) of the auditory system usually results in better speech understanding than electric stimulation only, assuming low-frequency hearing can be preserved. Treatment options and outcomes for 4 subjects experiencing compromised hearing after EAS surgery are discussed. Methods: Each subject underwent revision surgery to replace the original 21-mm electrode arrays used in EAS surgery with cochlear implants (CIs) with 31-mm arrays. Our aims were: (1) to investigate whether deeper insertion is possible, and (2) to evaluate the influence of electrode insertion angle by comparing speech perception scores before and after revision surgery. Results: Deeper insertion was feasible in all subjects. Speech understanding scores after reimplantation were comparable to those seen after the first intervention. Conclusion: A 360-degree insertion under EAS conditions provides sufficient speech understanding, even in cases of additional hearing loss. Reimplantation with a longer electrode array is feasible in former EAS patients.

Hearing Preservation and Hearing Improvement After Reimplantation of Pediatric and Adult Patients With Partial Deafness

“…Our data confirms that in EAS patients, residual low-frequency hearing can be preserved after reimplantation, which is in keeping with a recent and only report in the literature by Kamat et al (7). Other reimplantation outcomes in partial deafness patients in the (17), who described patients with partially preserved or compromised residual hearing after initial EAS surgery who were reimplanted with standard length electrodes and subsequently had no preservation of their residual hearing. The outcome of the child who was reimplanted with a Flex-EAS electrode is unique in that it is a successful reimplantation in a child with partial deafness who experienced device failure.…”

Evaluation of an Electrode Prototype for Atraumatic Cochlear Implantation in Hearing Preservation Candidates

“…Still, the measurements revealed that the applied insertion forces stayed below 0.025 N in meanVa fact that together with the histologic results of this study supports the use of the prototype electrode. Previous studies showed similar results for speech understanding in the CI-only condition with 360-degree insertion angle and deeper insertion with a 30-mm array (22). Confirming these results, a study implanting patients with a less deep 10-mm insertion depth found better performance after deeper reimplantation (14), indicating that shallower insertion angles do not show the same benefit.…”

Partial Deafness Treatment

“…This finding is consistent with results reported by Dorman et al (2009), who did not find any significant differences in speech perception performance between EAS condition compared with bimodal condition in patients implanted with the 10 mm Nucleus Hybrid electrode. Comparing speech perception scores before and after revision surgery in EAS cases, Helbig et al (2009) also concluded that 20 mm insertion provides sufficient speech understanding, even in cases of loss of hearing or non-functional preservation.…”