聽小骨成形術後之聽力改善－－預後因子分析

Hearing Results after Ossiculoplasty-An Analysis of Prognostic Factors

背景：慢性中耳炎患者常合併聽小骨缺損，重建聽小骨及恢復其功能是改善聽力的重要環節。其中，有許多因素會影響聽力的預後，本研究旨在回顧本院耳鼻喉科所執行之聽小骨成形術，並探討影響聽力預後的因素。方法：回顧2000年1月至2002年12月間，於本院接受Farrior's第三型鼓室成形術之病歷。紀錄手術前後之純音聽力檢查、術前症狀、術中發現、手術方式及術後追蹤情形。有完整記錄者，以下列條件來分組：1） 術前有無耳漏，2） 聽小骨缺損情形，3）乳突鑿開術的種類，4） 是否為再次手術，5） 重建之材料。進而分析個別因素與術後聽力的關係。結果：共105例手術，分別由3位專科醫師執行；平均術後追蹤9.4個月。術後傷口感染9例（8.6%）；耳膜穿孔未癒合者18例（17.1%）；術後復發3例（2.9%）；聽小骨突出4例（3.8%）。術後有純音聽力檢查者共52例，檢查時間平均為術後6.6個月。術後氣骨導閾值差 （air-bone gap, A-B gap） 平均為28.0分貝，與術前平均A-B gap 34.9分貝相比，有統計學上的差異 （P<0.001）。聽力預後因素分析結果，除了聽小骨重建材料之外，其他變項皆未達到統計上的差異。結論：本篇與其他研究結果不同的原因可能為：1） 主刀者不只一位，2） 病例數較少，3） 術後聽力追蹤的時間點較近。有賴更多經驗的累積以及更密切的追蹤，以期有更完善的研究結果。

BACKGROUND: Patients with chronic otitis media often have various kinds of defects of the ossicular chain. Reconstruction and restoration of the ossicular structure, ossiculoplasty, is one of the important procedures for hearing improvement in those patients. Several factors involve the prognosis of ossiculoplasty. This study aims to review the procedures and methods of ossiculoplasty performed in our hospital and analyze the possible prognostic factors effecting hearing outcomes. METHODS: We retrospectively reviewed the charts of the patients who received ossiculoplasty, from January 2000 to December 2002, as one of the procedures of type3 tympanoplasty in Farrior’s classification. The recorded data included pre- and post-operative hearing threshold, symptoms and signs before surgery, intraoperative findings, and postoperative complications during the period of follow up. These cases were subgrouped according to the following conditions: 1) pre-operative otorrhea or not. 2) the types of ossicular defect. 3) canal-wall-up or canal-wall-down mastoidectomy. 4) revised surgery or not. 5) materials used for reconstruction of the ossicular chain. The hearing results of each subgroups were compared and analyzed. RESULTS: There were 105 operations performed by 3 otolaryngologists. The mean follow-up time was 9.4 months. The post-operative complications were: wound infections: 9 cases(8.6%); unhealed perforation of the eardrum: 18 cases(17.1 %); recurrence of disease: 3 cases(2.9%); extrusion of the prosthesis or the ossicles: 4 cases(3.8%). The post-operative hearing threshold was available in 52 cases. The mean time of those examinations was 6.6 months postoperatively. The mean postoperative air-bone gap was 28.0 dB, and was statistically different from the mean preoperative air-bone gap: 34.9 dB(p<0.001). The hearing results showed significant difference when using different reconstructive materials. (autograft vs PORP, p=0.047), while no significant difference was found in other comparison. CONCLUSIONS: The results of our study differed from other studies. The reasons could be: 1) The procedures were not performed by the same surgeon. 2) The case number was too small for statistical analysis. 3) The mean length of time between the operation and post-op PTA was inuyfficient. More experiences as well as longer and closer follow-up were needed for more conclusive results.