Survey of the American Neurotology Society on Cochlear Implantation: Part 2, Surgical and Device-Related Practice Patterns
Authors: Carlson Matthew L. , O’Connell Brendan P. , Lohse Christine M. , Driscoll Colin L. , Sweeney Alex D. 
Published: November 2017

Objective:
To examine surgical and device-related cochlear implant practice patterns across centers in the United States.

Methods:
Cross-sectional survey of the American Neurotology Society (ANS).

Results:
A total of 81 surveys were returned from ANS members who report regular involvement in cochlear implant care. Overall there was a broad distribution in age and clinical experience, with most respondents reporting Accreditation Council for Graduate Medical Education (ACGME) accreditation in neurotology and employment at an academic center. The annual volume of cochlear implant surgeries varied considerably across centers. Eighty percent of respondents report to offer all three Food and Drug Administration (FDA) approved device brands at their center.
In cases where hearing preservation is not a goal, 56% of respondents prefer a perimodiolar electrode design, while 44% prefer a lateral wall electrode. With regard to insertion technique for scala tympani access, 64% prefer inserting through the round window (RW) membrane, 26% prefer an extended round window (ERW) approach, while only 10% prefer a cochleostomy. In cases where hearing preservation is a goal of surgery, 86% of respondents prefer a lateral wall electrode design, while only 14% prefer a perimodiolar electrode design. With regard to insertion technique, 86% prefer RW insertion, while only 9% prefer an ERW approach, and only 5% prefer a cochleostomy. Respondents who prefer RW electrode insertion more commonly use a lateral wall electrode, whereas those who prefer an ERW or cochleostomy approach more commonly use a periomodiolar electrode (p < 0.001). There was a statistically significant greater number of surgeons that prefer lateral wall electrodes (p < 0.001) and RW insertion (p < 0.001) for hearing preservation cases compared with non-hearing preservation cases. For implantation of a hypothetical patient with significant residual hearing, within the range of hybrid device candidacy, the great majority of surgeons prefer a conventional length electrode and only 29% prefer to implant a hybrid device.
In cases where hearing preservation is a goal, the overwhelming majority of respondents (96%, n = 74) reported using at least one form of steroid application. Ninety-two percent (n = 71) used intraoperative intravenous steroids, 55% (n = 42) prescribed postoperative oral steroids, 44% (n = 34) bathed the middle ear with steroids during surgery, and 30% (n = 23) prescribed preoperative oral steroids.
Together, 65% of respondents use a variation of the tight subperiosteal pocket technique for internal device fixation, 19% prefer a bony well and trough with tie-downs, 10% prefer a bony well and trough without tie-downs, and 5% prefer a screw fixation system. Of the 50 who prefer utilizing a subperiosteal pocket, 31 (62%) incorporate a bony trough and 19 (38%) perform a subperiosteal pocket alone without a bony trough.

Conclusion:
The results of this survey reflect the evolution in surgical and device-related preferences for cochlear implantation in the United States. An increasing number of surgeons prefer the RW approach for electrode insertion. When hearing preservation is not a goal, there is a near even preference for lateral wall and perimodiolar electrode designs; however, the great majority of surgeons prefer a lateral wall design when attempting to preserve residual acoustic hearing. Even in cases where substantial residual hearing exists, many surgeons prefer conventional length electrodes to hybrid designs. These changes reflect the prioritization of atraumatic surgery and parallel the development of thinner and more atraumatic electrodes.