外耳正常之先天性聽小骨異常

Congenital Ossicular Anomalies in Patients with a Normal External Ear

黃德種(Te-Chung Huang) ； 洪朝明(Chao-Ming Hung) ； 王拔群(Pa-Chun Wang) ； 林俊成(Jun-Chen Lin) ； 王仁鵬(Jen-Peng Wang) ； 張敬驩(Ching-Haun Chang) ； 陳威璋(Wei-Chang Chen)

《中華民國耳鼻喉科醫學雜誌》 34卷5期 (1999/09) Pp. 389-393

https://doi.org/10.6286/1999.34.5.389

摘要

背景：先天性聽小骨異常多合併有外耳異常，較少見於外耳正常者。病患聽力可藉由手術治療而獲得改善。然而術前並不易診斷，需進行鼓室探查術才可確定。
方法：本科自1991年至1997年間，共有8例無外耳異常外傳導性聽障患者，在本科接受鼓室探查術，於術中發現聽小骨異常。整理病史、聽力學檢查及手術發現，並分析手術後聽力結果，將資料提出報告。
結果：8名病患平均年齡22歲，男女各4名，術前氣骨差間距平均為39 dB，各例於術中均執行聽力重建。3例為鐙骨異常併足板固定，接受鐙骨切除術及人工鐙骨值入；1例為砧骨體缺失，接受異體砧骨插位術；另4例為砧骨長突缺失併鐙骨異常，接受全聽小骨置換物值入。術後聽力改善的有6耳，氣骨差間距從平均41 dB，進步到24.7dB。
結論：一般的觀念中，槌骨和砧骨源自第一鰓弓，而鐙骨源自第二鰓弓。從本報告的術中發現，可推論槌骨源自第一鰓弓，而部分之砧骨與鐙骨有相同來源，源自第二鰓弓。患者接受手術治療，其手術後聽力改善程度，視異常種類及聽小骨重建方式而有差異。

關鍵字

先天性聽小骨異常 ； 傳導性聽障 ； 聽小骨重建 ； 鰓弓

並列摘要

Background: Anomalies of the ossicles are commonly encountered in patients with a congenital anomaly of the external ear, and less frequently in patients with a normal external ear with a patent external meatus. Improvement of hearing can be achieved by surgical treatment.
Methods: Surgery was performed on 8 ears from 8 patients with conduc-tive hearing impairment without malformation of the external ear between 1991 and 1997. The following data were collected: the otological history, pre- and postoperative audiograms, intraoperative findings, and types of ossicular chain reconstruction.
Results: There were 4 men and 4 women, with an average age of 22 years. The average preoperative air-bone gap was 39 dB. Ossicular chain reconstruction was performed during surgery. Three cases were found with stapes anomalies and footplate fixation, and a stapedectomy with piston-wire prosthesis was performed. One patient had a missing incus body and was treated with homograft incus interposition. The other 4 patients had stapes anomalies and missing incus long processes. They were given a total ossicular replacement prosthesis. Six patients had improved hearing. Their average postoperative air-bone gap was 24.7 dB compaired to 41 dB preoperatively.
Conclusions: The general opinion is that the malleus and the incus are derived from the first branchial arch, whereas the stapes is derived from the second. The pattern of ossicular abnormality encountered in this series suggests that the whole malleus originates from the first branchial arch, while a part of the incus has the same origin as the stapes, the second branchial arch. The postoperative results depend on types of anomaly and surgery.

並列關鍵字

congenital ossicular anomaly ； conductive deafness ； ossicular chain reconstruction ； branchial arch