人工耳蝸植入的手術問題

Surgical Prooblems in Cochlear Implantation

對於兩耳極重度聽力損失且無法由傳統助聽器得到幫助的聽障病人，人工耳蝸植入已被全世界證實為安全且有效的方法。國內在過去十年，這種手術已經越來越普遍，然而有關國內人工耳蝸之外科問題並未報告過，本研究目的即針對本院病患接受人工耳蝸植入之手術問題進行探討。於1994年3 月至2001年9月之間，共有58位病人於本院接受人工耳蝸植入手術，男性29位，女性29位，其中 8位接受澳洲Nucleus 22型人工耳蝸（Cochlear Company, Sydney, Australia）植入，另外48位接受 Nucleus 24M 型人工耳蝸植入，其餘 2 位接受 Clarion S 型（Advanced Bionics Corporation, California, USA）人工耳蝸植入。病患年齡由1歲4個月到44歲2個月不等，41位（70.7%）年齡小於6歲，其中 21位（36.2%）小於3歲。術中所發現之問題有：（1）耳蝸鈣化4例，占6.9%，過去均有腦膜炎病史， 其中3位因耳蝸鈣化嚴重，術中我們在耳蝸的基底迴部位鑿一小段通道並置入部分電極。（2）內耳構造畸形呈共同腔室4例，占6.9%，術中由乳突腔內的耳囊（otic capsule）鑿洞插入電極束。（3）外淋巴液滲漏4例（6.9%）和腦脊髓液湧溢1例（1.7%），其中多數為大前庭導水管症，術中使用軟組織來密封耳蝸造口。術後早期問題包括：（1）傷口感染2例（3.4%），接受清創手術。（2）皮瓣壞死與植入物外露1 例（1.7%），此病患進行清創與接收刺激器重置手術。（3）顏面神經麻痺1例（1.7%），於術後1個月痊癒。 （4）眩暈有5例（8.6%），皆為短暫性，症狀於術後第二天獲得緩解。（5）手術後輕度發燒7例（12%），全部為小孩，發燒原因可能與脫水或麻醉藥作用有關，所有病患於術後1〜2天內迅速緩解。術後晚期問題包括：（1）耳膜珍珠瘤1例（1.7% ），經手術摘除。（2）機器失效3例（5.1% ），經重新植入新的人工耳蝸。我們的經驗顯示人工耳蝸植入手術的較大併發症發生率只6.9%，且均可經治療或再手術而痊癒。人工耳蝸植入對於重度聽力損失的患者是一種安全的手術，手術的併發症率可以由術前詳細評估、周詳手術計畫、熟練手術技巧與完善（好）的手術後照顧而減少到最低。

Cochlear implantation (Cl) has become more and more popular in our country in last ten years. However, the experience of surgical problems in cochlear implantation has not been reported in our country. This study accessed our experience of the surgical problems in cochlear implantation at the Department of Otolaryngology, National Taiwan University Hospital. During the period from Mar. 1994 through Sep. 2001, fifty-eight patients (29 male and 29 female) received cochlea implantation in our hospital for bilateral profound hearing impairment. Nucleus 22 device (Cochlear company, Sydney, Australia) was implanted in 8 patients, Nucleus 24M in 48 patients and the Clarion S (Advanced Bionics Corporation, California, USA) in 2 patients. Their ages range from 1 year and 4 month old to 44 year 2 month old at operation. We reviewed the medical records including surgical problems during implantation and post-operative follow up. There were forty-one patients below age of six (70.7%). Twenty-one cases were as young as 3 year-old or younger (36.2%). The intraoperative problems of cochlear implantation included severe cochlear calcification (4 cases, 6.9%), common cavity of inner ear (4 cases, 6.9%), perilymphatic leakage (4 cases, 6.9%) and CSF gush out (1 case, 1.7%). We drilled a small tunnel along the basal turn and inserted parts of electrodes for 3 cases with severe cochlear calcification. We performed a small fenestration over otic capsule for insertion of electrodes via mastoid cavity in all 4 cases with common cavity. We used soft tissue to seal the cochleostoma after electrode insertion for cases with perilymphatic leakage or CSF gush out. Our experience showed that the incidence of surgical major complication was 6.9% for cochlear implantation. Postoperative major complications included wound infection, flap defect with exposure of receiver-stimulator and facial palsy. Development of a new flap with reposition of device was performed for the only case with flap defect. The case with mild facial palsy recovered completely in 1 month. Other minor postoperative problems were vertigo (5 cases, 8.6%) and low grade fever (7 cases, 12%). Those symptoms were all temporary and relieved soon in post-operative 2 to 3 days. Careful pre-operative evaluation, detailed surgical planning, skilled surgical technique and good post-operative care could minimize the surgical complication.