Department of Otolaryngology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
Otolaryngol Head Neck Surg. 2020 May;162(5):718-724. doi: 10.1177/0194599820904941. Epub 2020 Feb 25.
Studies suggest lateral wall (LW) scala tympani (ST) height decreases apically, which may limit insertion depth. No studies have investigated the relationship of LW ST height with translocation rate or location.
Retrospective review.
Cochlear implant program at tertiary referral center.
LW ST height was measured in preoperative images for patients with straight electrodes. Scalar location, angle of insertion depth (AID), and translocation depth were measured in postoperative images. Audiologic outcomes were tracked.
In total, 177 ears were identified with 39 translocations (22%). Median AID was 443° (interquartile range [IQR], 367°-550°). Audiologic outcomes (126 ears) showed a small, significant correlation between consonant-nucleus-consonant (CNC) word score and AID ( = 0.20, = .027), although correlation was insignificant if translocation occurred ( = 0.11, = .553). Translocation did not affect CNC score ( = .335). AID was higher for translocated electrodes (503° vs 445°, = .004). Median translocation depth was 381° (IQR, 222°-399°). Median depth at which a 0.5-mm electrode would not fit within 0.1 mm of LW was 585° (IQR, 405°-585°). Median depth at which a 0.5-mm electrode would displace the basilar membrane by ≥0.1 mm was 585° (IQR, 518°-765°); this was defined as predicted translocation depth (PTD). Translocation rate was 39% for insertions deeper than PTD and 14% for insertions shallower than PTD ( = .008).
AID and CNC are directly correlated for straight electrodes when not translocated. Translocations generally occur around 380° and are more common with deeper insertions due to decreasing LW ST height. Risk of translocation increases significantly after 580°.
研究表明，外侧壁（LW）鼓阶（ST）高度在上部逐渐降低，这可能限制了插入深度。目前尚无研究调查 LW ST 高度与转位率或位置的关系。
回顾性研究。
三级转诊中心的人工耳蜗植入项目。
对具有直电极的患者的术前图像进行 LW ST 高度测量。在术后图像中测量了标度位置、插入深度角（AID）和转位深度。跟踪听力结果。
共确定 177 只耳朵有 39 个转位（22%）。中位 AID 为 443°（四分位距[IQR]，367°-550°）。听力结果（126 只耳朵）显示，辅音-核-辅音（CNC）词得分与 AID 之间存在小而显著的相关性（ = 0.20， =.027），尽管转位发生时相关性不显著（ = 0.11， =.553）。转位对 CNC 评分没有影响（ =.335）。转位电极的 AID 更高（503° vs 445°， =.004）。中位转位深度为 381°（IQR，222°-399°）。中位数为 0.5mm 电极在距离 LW 0.1mm 以内不会适合的深度为 585°（IQR，405°-585°）。中位数为 0.5mm 电极将基底膜位移≥0.1mm 的深度为 585°（IQR，518°-765°）；这被定义为预测转位深度（PTD）。插入深度大于 PTD 时，转位率为 39%，插入深度小于 PTD 时，转位率为 14%（ =.008）。
当未转位时，AID 和 CNC 与直电极直接相关。转位通常发生在 380°左右，由于 LW ST 高度降低，较深的插入更常见。在 580°之后，转位的风险显著增加。
