Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, Minnesotta.
Otol Neurotol. 2022 Sep 1;43(8):e880-e887. doi: 10.1097/MAO.0000000000003620.
To determine the relationship between intraoperative electrocochleography (ECochG) measurements and residual hearing preservation after cochlear implant (CI) surgery by comparing differences between preoperative and immediate postoperative bone conduction thresholds.
Prospective cohort study.
Tertiary academic referral center.
Sixteen patients with preoperative residual hearing and measurable (no-vibrotactile) bone conduction thresholds at 250 and/or 500 Hz who underwent cochlear implantation.
Intraoperative ECochG and air and bone conduction thresholds.
Nine patients showed no significant drop (<30%) in ECochG amplitude during CI surgery with an average preoperative and immediate postoperative BC threshold of 46 and 39 dB HL, respectively, at 500 Hz. Seven patients with a decrease in ECochG amplitude of 30% or greater showed an average preoperative 500 Hz BC threshold of 32 dB HL and immediate postoperative threshold of 55 dB HL. Air and bone conduction thresholds measured approximately 1 month after CI surgery show delayed-onset of hearing loss across our study patients.
A small decrease (<30%) in difference response or cochlear microphonics amplitude correlates with no significant changes in immediate postoperative residual hearing, whereas patients who show larger changes (≥30%) in difference response or cochlear microphonics amplitude during intraoperative ECochG measurements show significant deterioration in BC thresholds. This study reveals the necessity of prompt postoperative bone conduction measurement to isolate the intraoperative cochlear trauma that may be detected during intraoperative ECochG measurements. Although delayed postoperative audiometrics represent longer-term functional hearing, it includes the sum of all postoperative changes during the recovery period, including subacute changes after implantation that may occur days or weeks later. Measuring air and bone conduction thresholds immediately postoperatively will better isolate factors influencing intraoperative, early postoperative, and delayed postoperative hearing loss. This will ultimately help refine surgical technique, device design, and highlight the use of intraoperative ECochG in monitoring cochlear trauma during CI surgery.
通过比较术前和即刻术后骨导阈值的差异，确定术中电 CochG（ECochG）测量值与人工耳蜗植入（CI）术后残余听力保留之间的关系。
前瞻性队列研究。
三级学术转诊中心。
16 例术前有残余听力且可测量（无振动触觉）250Hz 和/或 500Hz 骨导阈值的患者，行人工耳蜗植入术。
术中 ECochG 及气导和骨导阈值。
9 例患者在 CI 手术过程中 ECochG 幅度无明显下降（<30%），平均术前和即刻术后 500Hz 骨导阈值分别为 46dBHL 和 39dBHL。7 例患者 ECochG 幅度下降 30%或以上，平均术前 500Hz 骨导阈值为 32dBHL，即刻术后阈值为 55dBHL。CI 手术后约 1 个月测量气导和骨导阈值，提示我们研究中的患者听力损失出现迟发性。
差异反应或耳蜗微音器幅度的小幅度下降（<30%）与即刻术后残余听力无显著变化相关，而术中 ECochG 测量中差异反应或耳蜗微音器幅度变化较大（≥30%）的患者，其骨导阈值则显著恶化。本研究揭示了即刻术后骨导测量的必要性，以分离术中 ECochG 测量时可能检测到的耳蜗创伤。虽然延迟的术后听力测试代表了更长时间的功能性听力，但它包括了恢复期内所有术后变化的总和，包括植入后数天或数周后可能发生的亚急性变化。术后即刻测量气导和骨导阈值将更好地分离影响术中、早期术后和迟发性术后听力损失的因素。这最终将有助于改进手术技术、设备设计，并强调在 CI 手术中使用术中 ECochG 监测耳蜗创伤。
