人工耳蝸植入者術後遙測阻抗值之變化

Postoperative Changes of Telemetry Impedance in Patients with Cochlear Implants

葉峻維(Chun-Wei Yeh) ； 王培霖(Pei-Lin Wang) ； 楊昭輝(Chao-Hui Yang) ； 彭治平(Jyh-Ping Peng) ； 黃仲鋒(Chung-Feng Hwang)

《台灣耳鼻喉頭頸外科雜誌》 51卷3期 (2016/09) Pp. 180-187

https://doi.org/10.6286/2016.51.3.180

摘要

背景：對於傳統助聽器治療無效的重度和極重度聽障者，藉由手術植入人工耳蝸進行復健已經變成是醫療上普遍接受的治療方式。植入後使用遙測可用於測量電極阻抗，可以通信檢查植入人工耳蝸的電極是否故障及完整性。本研究是設計針對人工耳蝸植入者測量並記錄在手術植入時與手術後開機製圖(mapping)時，其遙測阻抗值(telemetry impedance)的變化，並比較不同電極模式、年齡、耳蝸構造和植入體等其阻抗變化是否有差異。材料與方法：以病歷回顧方式，收集2010年11月至2015年1月期間，在高雄長庚醫院接受人工耳蝸手術患者，進行分析醫療記錄和相關電極電阻遙測數據，包含術中和手術後開機製圖時相關資料。電極阻抗遙測是對所有22個電極測量阻抗值，阻抗用製造商的模式測定：地極(CG)和三個單極模式(MP1，MP2，或MP1+2)，記錄單位是Kohm，任何異常短路或開放電極都會記錄並且關閉使用。結果：本院46名人工耳蝸病患，其中男26名，女20名，平均手術年齡10.4歲(範圍1到64歲)，左耳植入佔29耳，右耳植入佔17耳，平均術後開機調頻時間是22.4天(範圍2到41天)，電極故障率僅0.2-0.4%。術後開機製圖的4種電極阻抗值皆顯著高於術中測得阻抗(p ＜ 0.001)，4種模式中其阻抗值大小依序是MP1 ＞ MP2 ＞ MP1+2 ＞ CG，相互間皆有明顯差異(p ＜ 0.001)。另外術後開機調頻時間小於28天、成人(大於等於18歲)及有內耳構造畸形這幾組其阻抗值在術後開機製圖測得的四個模式阻抗值都明顯比大於等於28天、小孩(小於18歲)及無內耳構造畸形組來的低(p ＜ 0.001)。分析858個彎電極片(CI24RE和CI512)和154個直電極片(CI422)的阻抗，僅於術後開機製圖時測量直電極的電極阻抗值明顯高於彎電極。結論：本研究發現CI遙測電極電阻值可以提供電極是否完整的重要訊息，但在不同的測量模式、時間、年齡、電極束甚至有無內耳構造畸形其阻抗都會有差異，這些阻抗變化與將來預後是否具相關性，需要進一步研究。

關鍵字

impedance telemetry ； cochlear implant ； electrical stimulation（阻抗遙測 ； 人工耳蝸 ； 電刺激）

並列摘要

BACKGROUND: Surgical rehabilitation by cochlear implant (CI) has become a well-accepted treatment in case of severe-to-profound hearing loss in which conventional amplification is not helpful. Telemetry could be used as the measurement for the impedance of the electrodes after cochlear implantation and allows us to communicate with the CI system to detect electrodes failure and its function. Our study conducted on CI recipients, to monitor changes in telemetry impedance measured during surgery versus initial mapping after CI on different electrode mode, age, cochlear structure and implant mode. METHODS: In our retrospective chart review study, we enrolled patients receiving CI in Kaohsiung Chang Gung Memorial Hospital between November 2010 and January 2015. We analyzed the medical records, impedance telemetry data of the associated electrode modes both during intra-operative and post-operative periods. The electrical impedance to all 22 electrodes were measured at each time. The impedance data was measured by manufacturing company original setting modes including common ground (CG) mode and three mono-polar modes (MP1, MP2 and MP1+2). The unit is recorded as Kohm and any abnormal short or open circuits will be recorded and shut down. RESULTS: There were 46 patients (26 males and 20 females) with the average age 10.4 years old (1~64 years old) undergoing CI (including 29 left ears and 17 right ears). The average post implant initial mapping time is 22.4 days (2-41 days) and the electrode failure rate is merely 0.2% to 0.4%. The initial mapping impedance data were higher than intra-operative in each four different modes with significant difference (p ＜ 0.001) and revealed MP1 ＞ MP2 ＞ MP1+2 ＞ CG in sequence. We also found the initial mapping impedance were significant higher(p ＜ 0.001) in the subgroup of post implant initial mapping time less than 28 days, age older than 18 years-old and with inner ear structural abnormalities compared to another opposite groups. By analyzing the impedance between 858 curved electrodes (CI24RE and CI512) and 154 straight electrodes, straight electrodes show significant higher impedance than the curved electrodes but only in the initial mapping period. CONCLUSIONS: In our study, we found that telemetry impedance in CI provides valuable information regarding the integrity of electrodes. However, it still needs further investigation whether the impedance differences between different setting modes, times, age, type of electrode arrays and inner ear structural abnormalities play the predicting role for the CI patients' performance in the future.

並列關鍵字

impedance telemetry ； cochlear implant ； electrical stimulation