To evaluate hearing preservation
(HP) outcomes in adult cochlear implant recipients with a mid-scala electrode.
Tertiary academic center.
Adult patients implanted with a mid-scala electrode between May 2013 and July 2015.
Interventions: Cochlear implantation
Main Outcome Measure(s):
Age, sex, surgical approach, residual hearing changes post cochlear implantation
, HP rates using different published classifications, and speech perception scores.
Fifty ears for 47 patients (mean age, 58.2 yr; range, 23–86) were implanted with the electrode. Recognizing that not all patients were true HP candidates and/or underwent generally accepted HP surgical techniques, 39 ears had preoperative low-frequency hearing (audiometric threshold ≤85 dB HL at 250 Hz), 24 preserved acoustic hearing postoperatively (75.0%). Patients who had preserved acoustic hearing were implanted via round window (N = 18), extended round window (N = 4), or via cochleostomy (N = 2) approaches. Mean threshold elevation for low-frequency pure-tone average (125, 250, and 500 Hz) was 20.2 dB after surgery. 43.8% of patients had aidable low-frequency hearing at activation, 30.0% at 6-months postoperatively, and 30.8% 1-year postoperatively. Using a formula outlined by Skarzynski and colleagues, at 6-months postoperatively, 15.0% of patients had complete HP, whereas 40.0% had partial HP. At 1-year, these percentages decreased to 0% and 38.5%, respectively. Age, type of approach, and perioperative steroid use were not correlated with HP outcomes at activation and 6-months postoperatively (p
The mid-scala electrode evaluated allows preservation of low-frequency hearing in patients undergoing cochlear implantation
at rates and degrees of preservation close to other reports in the cochlear implant literature.