Immediate and 1‐Year Outcomes with a Slim Modiolar Cochlear Implant Electrode Array

Abstract

Objective To explore the immediate and 1-year outcomes of patients who underwent implantation with the slim modiolar electrode (SME). Study Design Consecutive case series with chart review. Setting Tertiary referral academic center. Subject and Methods Between May 2016 and August 2018, a total of 326 cochlear implantations (CIs) were performed. Intraoperative x-rays were performed in all cases to identify tip rollovers. Scalar location was identified for 76 CIs that had postoperative computed tomography reconstructions. Speech outcomes were measured at 3, 6, and 12 months with consonant-nucleus-consonant word and AzBio sentences in quiet and noise (+10-dB signal-to-noise ratio). Preservation of hearing was defined as maintaining a low-frequency pure tone average ≤80 dB at 250 and 500 Hz. Results Among 326 CIs, 23 (7%) had tip rollovers. Postoperative reconstructions revealed 5 of 76 (6.6%) scalar translocations. A subset of 177 cases met criteria for evaluation of speech perception scores. The marginal mean differences between presurgery and 12 months for speech tests were as follows: consonant-nucleus-consonant, 43.7 (95% CI, 39.8-47.6); AzBio in quiet, 49.7 (95% CI, 44.9-54.4); and AzBio in noise, 29.9 (95% CI, 25.2-34.7). Sixty-one patients were identified with preservable hearing (low-frequency pure tone average ≤80 dB), and 12 of 61 (20%) preserved hearing at 1 year. Conclusion CI with SME provides reliable scala tympani insertion in a consistent perimodiolar position. An initially increased tip rollover rate improved with case volume and sheath design improvement. For long-term outcomes, speech performance was comparable to that of other cochlear implants. While hearing preservation for the SME may be better than prior perimodiolar electrodes, consistent outcomes are unlikely.

Scalar Translocation Comparison Between Lateral Wall and Perimodiolar Cochlear Implant Arrays ‐ A Meta‐Analysis

“…Six studies described the TF rate of the CI-532 electrode array. 12,23,[29][30][31]44 From a total of 622 implantations, 37 TFs were identified, resulting in a TF rate of 5.9% for the CI-532. Finally, for the remaining three studies, two studies reported one TF, 38,39 and one study 41 reported no TF.…”

Intracochlear electrode array position and cochlear implant outcomes using the nucleus slim modiolar electrode and the extended round window approach: a follow-up study

“…These results are an evident improvement compared to previously reported implantations via a cochleostomy approach at our center, and generally comparable to what is reported in the literature, although studies adequately reporting on the CT-evaluated scalar position by surgical approach for the SME are still relatively scarce. The studies in which this was determined using high-resolution imaging result in a combined average translocation risk of 4.8% (22/461) [4,[18][19][20][21][22][23][24]. Of these aggregated 461 participants, 396 could be identified as having been implanted using either a RW or eRW approach and 39 as implanted using a CS approach [4,18,20,21,23,24].…”

Simpler and effective radiological evaluations for modiolar proximity of a slim modiolar cochlear implant electrode

“…The slim modiolar electrodes have been reported to provide a consistently higher scalar tympani position than conventional perimodiolar electrodes 6 , 14 . In addition, 4.1–4.6% rate of tip-fold over has been reported in the literature 9 , 14 , but tend to gradually decrease with experience 15 . Thus, specifically for slim modiolar electrodes, degree of modiolar proximity may be one of the critical determinants of better auditory performance.…”