An evidence-based algorithm for intraoperative monitoring during cochlear implantation.
OBJECTIVE
To generate an evidence-based algorithm for the use of intraoperative testing during cochlear implantation (CI).


METHODS
Retrospective review.


METHODS
Tertiary referral center.


METHODS
A total of 277 children (aged 6 mo to 17 yr) and adults 18 years and older with normal cochlear anatomy who underwent primary and revision cochlear implantation at a single center between 2005 and 2010 were included.


METHODS
Intraoperative electrophysiologic monitoring and intraoperative Stenver's view plain film radiography.


METHODS
Intraoperative testing included the following: 1) individual electrode impedance measurements; 2) neural response telemetry (tNRT) levels for electrodes E20, E15, E10, and E5; and 3) plain film radiograph assessment of electrode position.


RESULTS
No patient demonstrated abnormalities on all 3 modalities. Open or short electrodes on impedance testing were found in 6% of patients; half of these normalized when remeasured. Absent tNRT responses on 1 or more electrodes occurred in 14% of patients, although complete lack of response was rare (1.4%) and did not correlate with a dysfunctional device. Spread of excitation was performed in 1 patient and was consistent with a tip rollover. Intraoperative radiography identified tip-rollover and extracochlear electrode placement in all cases (n = 5, 1.8%) and prompted the use of the backup device.


CONCLUSIONS
Immediate intraoperative determination of device functionality and optimal electrode placement is advantageous. Of the modalities tested, including electrode impedance, tNRT, and plain radiograph, only the radiographic results impacted intraoperative surgical decision making and led to the use of the backup device.
Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, New York 10016, USA. maura.cosetti@nyumc.org
Maura K
MK
Cosetti
Scott H
SH
Troob
Jonathan M
JM
Latzman
William H
WH
Shapiro
John Thomas
JT
Roland
Susan B
SB
Waltzman
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000000981:diagnostic imaging / Q000601:surgery; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D017097:Electric Impedance; D004566:Electrodes; D004569:Electroencephalography; D055724:Electrophysiological Phenomena; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008416:Mastoid / Q000601:surgery; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D013506:Otologic Surgical Procedures; D011859:Radiography; D012189:Retrospective Studies; D012984:Software; D013686:Telemetry; D014433:Tympanoplasty; D055815:Young Adult