The Influence of Intraoperative Testing on Surgical Decision-making During Cochlear Implantation

Abstract

Our data suggest that with respect to CI in children and adults in straightforward cases (e.g., normal anatomy, nondifficult insertion, etc.), routine intraoperative evoked compound action potentials, impedances, and imaging rarely influence surgical decision-making in our clinic and may have limited usefulness in these patients. The implications of this are discussed and a review of the literature is presented.

Cochlear Implant Performance in Adult Patients with Absent Intraoperative Electrically Evoked Compound Action Potentials

“…ECAP may be absent secondary to air bubbles within the cochlea, which affect electrophysiologic testing. 6 Since ECAP is a measure of spiral ganglion and cochlear nerve function, absent ECAP may be the result of severe dysfunction of these neural elements in the auditory pathway. 11 Interestingly, Eftekharian et al 17 found statistically significant increases in intraoperative ECAP thresholds with increased depth of anesthesia.…”

“…Several causes for absent intraoperative ECAP have been hypothesized. ECAP may be absent secondary to air bubbles within the cochlea, which affect electrophysiologic testing 6 . Since ECAP is a measure of spiral ganglion and cochlear nerve function, absent ECAP may be the result of severe dysfunction of these neural elements in the auditory pathway 11 .…”

“…1,3-5 The measurements may be used both to confirm cochlear implant electrode placement and functionality, as well as to aid audiologists with initial programming when the device is activated, which may be of particular benefit in children and other patients who may have difficulty with active participation. 2,6…”

“…ECAP measurements are performed at many cochlear implant centers intraoperatively by either an audiologist present in the operating room or through a remote connection 1,3–5 . The measurements may be used both to confirm cochlear implant electrode placement and functionality, as well as to aid audiologists with initial programming when the device is activated, which may be of particular benefit in children and other patients who may have difficulty with active participation 2 , 6 …”

“…1,[3][4][5] The measurements may be used both to confirm cochlear implant electrode placement and functionality, as well as to aid audiologists with initial programming when the device is activated, which may be of particular benefit in children and other patients who may have difficulty with active participation. 2,6 A clear relationship between ECAP measurements and cochlear implant performance has not been established. 1,5,7,8 Although ECAP measures can be reliably achieved, in a small number of patients, responses are not able to be obtained.…”