慢性化脓性中耳炎鼓室成形术前后骨导听阈变化的临床观察

Clinical study of the bone conduction thresholds before and after tympanoplasty in chronic suppurative otitis media

目的:探讨慢性化脓性中耳炎术前骨导听阈提高与术后骨导听阈变化的相关因素。方法:单侧慢性化脓性中耳炎行鼓室成形术45例,术前3d内和术后3个月分别行常规纯音测听,术前患侧与健侧相比,骨导听阈0.25～8.00kHz至少连续2个或2个以上频率增加≥10dB为术前骨导听阈提高阳性;术后3个月与术前相比,0.25～8.00kHz至少2个或2个以上频率减少≥10dB为术后骨导听阈下降阳性,增加≥10dB为术后骨导听阈提高阳性。结果:45例中35例(77.8%)术前骨导听阈提高阳性,与病程长短、是否伴有胆脂瘤无关,但与听骨链破坏有相关性(P<0.05),听骨链中断易导致术前骨导听阈提高;术前骨导听阈提高阳性35例中有6例(17.1%)术后骨导听阈下降阳性;45例患者中有5例(11.1%)术后骨导听阈提高阳性。结论:慢性化脓性中耳炎可造成骨导听阈提高,鼓室成形术不仅可使气导听阈下降、缩小气骨导差,还可使骨导听阈下降;术中过多触动听骨链及噪声等可造成术后骨导听阈提高。

Objective：To study the relative factors of the changes of preoperative and postoperative bone conduction thresholds in chronic suppurative otitis media. Method：The preoperative and postoperative bone conduction thresholds were prospectively investigated in 45 patients with unilateral chronic suppurative otitis media after tympanoplasty. Preoperatively （within 3 days before operation）, 10 dB or more depression of bone conduction threshold at least in consecutive 2 frequencies between 0.25 kHz and 8.00 kHz was considered to be significant. Similarly in the postoperative period （3 months after operation）, 10 dB or more improvement or impairment of bone conduction threshold at least in consective 2 frequencies between 0.25 kHz and 8.00 kHz was regarded as significant. Result：Thirty-five of 45 cases（77.8% ） were found to have depressed bone conduction threshold before operation, 6 of 35 cases （17.1%） had improved bone conduction thresholds and 5 of 45 cases （11.1%） had depressed bone conduction thresholds after tympanoplasty. Conclusion： In cases with chronic suppurative otitis media, successful results could be achieved after tympanoplasty disregarding air conduction threshold, the air-bone gap and deteriorated bone conduction threshold. Impairment of bone conduction thresholds could be induced by chronic suppurative otitis media itself and could also be induced by touching the ossicle chain rudely and by the noise of drilling during the operation.