Do Perioperative Systemic Corticosteroids Improve Cochlear Implant Hearing Preservation Outcomes?

LITERATURE REVIEW The use of corticosteroids in HP in CI is supported by multiple animal studies involving guinea pigs. In a recent systematic review of the animal literature, Shaul et al. examined 155 guinea pigs who were treated with topical middle ear glucocorticoids, as well as 50 guinea pigs treated with systemic corticosteroids, compared to controls. With regard to topical treatment, the delivery of corticosteroid to the round window at least 30 minutes prior to CI resulted in decreased threshold shifts in high frequencies (4–32 kHz), which extended to lower frequencies when applied 1 day prior to CI. Steroid application immediately prior to insertion of the electrode array had no effect. Systemic glucocorticoids also resulted in reduced threshold shift in frequencies between 4 kHz and 24 kHz on the scale of 10 dB, though the timing of systemic steroid administration was unclear. There have also been several reports on the use of corticosteroids in human subjects undergoing CI. Sweeney et al. specifically studied the effect of oral corticosteroid administration on HP with a retrospective review of 27 patients. Styleted perimodiolar arrays were used for 35% and 28.6% of steroid and non-steroid group, respectively; all other patients were implanted with lateral wall arrays. Complete electrode array insertion was achieved in all subjects with 92.6% being inserted using round window approach. Twenty patients received a perioperative prednisone taper starting 3 days prior to surgery and lasting a total of 16 days (60 mg for 6 days, then taper by 10 mg every other day), while seven patients did not receive any oral steroids. Of note, both groups received intraoperative intravenous dexamethasone and topical dexamethasone application to the round window. Using a ratio of the difference of postoperative pure-tone average (PTA) and preoperative PTA to the difference of maximum PTA and preoperative PTA, Sweeney et al. calculated that a median 45.5% of acoustic hearing was preserved in the corticosteroid group compared to a median of 6.6% in the control group, P < . 01. Using a definition of 80 dB or better at 250 Hz as HP, no patient in the control group had HP compared to 47.4% of the steroid group, P = . 02. HP in the steroid group dropped by median 4.8% from the first postoperative audiogram to the latest postoperative audiogram at a median of 8.6 months after the surgery. Kuthubutheen et al. conducted a prospective randomized controlled trial of patients implanted with Med-El Flex 28 electrodes. The patients were randomized into a control group (11 patients), another group treated with a 6 day preoperative oral steroid course of 1 mg/kg/day of prednisolone (max 60 mg/day) (10 patients), and another group treated with 5 mg of intratympanic (IT) dexamethasone 24 hours prior to CI (nine patients). Using the PTA formula used by Sweeney et al. for HP, Kuthubutheen et al. found that mean percentage of hearing preserved was significantly higher in the IT steroid group (42.9% IT vs. 25.6% oral vs. 32.5% control) at 3 months postoperatively. However, at 12 months postoperatively, there was no significant difference (32.8% IT vs. 27.8% oral vs. 25.9% control). Cho et al. prospectively examined 19 patients implanted with Med-El Flex 28 and Cochlear 422 electrodes who received IV dexamethasone 24 hours and 1 hour prior to surgery with topical application of 2.5 mg of dexamethasone to the round window at the time of CI. From the Department of Otolaryngology–Head and Neck Surgery (D.E.K., J.W.K., J.B.H., B.I.), University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A. Editor’s Note: This Manuscript was accepted for publication on March 20, 2021. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Brandon Isaacson, MD, FACS, Department of Otolaryngology–Head and Neck Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9035. E-mail: brandon.isaacson@utsouthwestern.edu