Auditory Brainstem Implantation: The University of Verona Experience

Abstract

We believe that the RS approach is the route of choice for patients who are candidates for ABI due to the easy and clear access to the cochlear nucleus area. This route avoids some of the drawbacks of the translabyrinthine approach, such as mastoidectomy, labyrinthectomy, sealing of the cavity and posterior fossa with abdominal fat, and contamination from the middle ear. For this reason, it is the route of choice in children with cochlear nerve aplasia or severe cochlear malformation and in adults with complete ossification of the cochlea or cochlear nerve disruption due to cranial trauma.

Auditory Brainstem Implants in Children: Results Based on a Review of the Literature

“…The hearing and speech evaluation of the implantees has been performed in different ways among authors. Colletti et al [1,6,9,22] and Kalamarides et al [15] tested hearing using the following tests: (1) recognition of environmental sound or sound detection test; (2) closed-set vowel confusion test; (3) closed-set consonant confusion test; (4) closed-set word recognition in the vision-only mode (lip-reading), sound-only mode, and "sound plus-vision mode"; (5) open-set sentence recognition in the vision-only mode, sound-only mode, and sound-plus-vision mode; and (6) speech-tracking test [9,18] . Goffi-Gomez et al [13] and Eisenberg et al [24] used the "Infant Toddler Meaningful Auditory Integration Scale" (IT-MAIS) to evaluate hearing capacity and the "Meaningful Use of Speech Scale" (MUSS) to evaluate speech performance.…”

“…The translabyrinthine approach is the only one allowed by the FDA, [15,22] as it is considered by some authors as the most straightforward way to the foramen of Luschka, but experimental evidence suggests the necessity for more manipulation in order to observe the lateral recess, increasing the risks [22] . Bento et al [19] showed the feasibility of exposing of the jugular bulb without complications when using the retrolabyrinthine approach.…”

“…In order to activate the ABI, some authors [6,22] state that the first step is to define the threshold (T) and the maximum comfort levels (C). There are no tonotopic relationships between the ABI array and the human cochlear nucleus; so, 'place-pitch scaling' and 'ranking' are performed to determine the pitch perception and define the tonotopic array order.…”

“…Theoretically, this new strategy could improve the transmission of temporal and spectral speech information [3] . The Pulsar CI100 ABI ® is capable of activation by the CIS technique [7,22] .…”

“…Regarding the surgical procedure, 4 patients [13] were fitted with ABIs with the retrolabyrinthine approach, 8 with the suboccipital approach [14] , 49 with the retrosigmoid approach, [10,18,21] and 2 with the translabyrinthine approach [1,3,6,7,9,[13][14][15][22][23][24] . Both patients with bilateral schwannomas and tumors caused by NF2 received the retrosigmoid and transmeatal combined approaches for tumor removal.…”