Abstract
Objective To report our technique and experience using a retrosigmoid craniotomy approach for
auditory brainstem implantation (ABI) placement in adult neurofibromatosis type 2
(NF2) patients.
Design Retrospective case series.
Setting Single-center study, Boston, Massachusetts, United States.
Participants All NF2 patients who underwent evaluation at Massachusetts Eye and Ear Infirmary
and surgery at Massachusetts General Hospital from 2009 to 2013 were reviewed. Six
cases of retrosigmoid craniotomy for ABI surgery in five adult NF2 patients were identified.
The clinical history, operative course, and outcomes in these patients were reviewed.
Main Outcome Measures Postoperative complications and audiological outcomes.
Results Indications for ABI surgery were profound hearing loss associated with growth or
treatment of bilateral vestibular schwannomas. In all cases, a retrosigmoid craniotomy
was performed for tumor resection and ABI placement without complication. Electrode
placement was confirmed intraoperatively using electrical-evoked auditory brainstem
responses. The ABI was activated in the awake patient 4 to 6 weeks postoperatively.
Audiological testing was used to evaluate sound detection and speech perception with
the ABI. There were no cases of cerebrospinal fluid leak.
Conclusion Retrosigmoid craniotomy is a safe and effective means to provide access to the cochlear
nucleus for ABI placement following tumor resection in the adult NF2 patient. Preliminary
data indicate that this approach has few complications while offering benefits for
hearing. The retrosigmoid craniotomy should be considered a reasonable alternative
to the traditional translabyrinthine approach for placement of the ABI in deaf patients
who are not candidates for the cochlear implant.
Keywords
auditory brainstem implant (ABI) - neurofibromatosis type 2 (NF2) - retrosigmoid craniotomy
