Carrillo Ryner Jose C, Yang Nathaniel W, Abes Generoso T
Department of Anatomy, Philippine General Hospital, Ermita, Manila, Philippines.
Otol Neurotol. 2007 Dec;28(8):1034-7. doi: 10.1097/MAO.0b013e31815882a6.
To analyze the likelihood ratios (LRs) and predictive values of preoperative air-bone gap (ABG) levels on the presence of gross ossicular discontinuity (OD) among chronic suppurative otitis media (CSOM) patients.
Tertiary hospitals.
Records of 276 patients with CSOM 7 to 75 years old undergoing their first tympanomastoidectomy were reviewed. Association of preoperative audiogram on the presence of OD was analyzed using logistic regression analysis and chi 2 tests. Frequency-specific ABG values were compared with the presence of OD.
In CSOM without cholesteatoma, the ABG of 20 dB or less at 500 Hz (LR [-], 0.119; 95% confidence interval [CI], 0.016-0.867) and 30 dB or less at 1 kHz (LR [-], 0.276; 95% CI, 0.087-0.876) decreased probability of OD from 33 to 5.6% and 15.5%, respectively. Air-bone gap levels of greater than 30 dB at 2 kHz (LR [+], 2.8; 95% CI, 1.4-5.9) and greater than 40 dB at 4 kHz (LR [+], 2.2; 95% CI, 1.2-3.9) increased the probability of OD from 33 to 51 to 89%. In the presence of cholesteatoma, the chance of OD was 88%. The ability of ABG to alter probability of OD was not significant in the presence of cholesteatoma.
Narrow ABG at lower frequencies suggested absence of OD. Wide ABG at higher frequencies suggested presence of OD. Simple tympanoplasty can be done to patients with a small chance of OD as assessed by pure-tone audiometry, whereas a mandatory exploration of the ossicular chain with possible reconstruction was suggested on subjects with a high chance of OD. The presence of cholesteatoma warrants ossicular chain exploration.
分析慢性化脓性中耳炎（CSOM）患者术前气骨导间距（ABG）水平对严重听骨链中断（OD）存在情况的似然比（LRs）及预测价值。
三级医院。
回顾了276例年龄在7至75岁、首次接受鼓室乳突切除术的CSOM患者的记录。使用逻辑回归分析和卡方检验分析术前听力图与OD存在情况之间的关联。将特定频率的ABG值与OD的存在情况进行比较。
在无胆脂瘤的CSOM中，500Hz时ABG为20dB或更低（LR[-]，0.119；95%置信区间[CI]，0.016 - 0.867）以及1kHz时ABG为30dB或更低（LR[-]，0.276；95%CI，0.087 - 0.876）分别将OD的概率从33%降至5.6%和15.5%。2kHz时ABG大于30dB（LR[+]，2.8；95%CI，1.4 - 5.9）以及4kHz时ABG大于40dB（LR[+]，2.2；95%CI，1.2 - 3.9）将OD的概率从33%提高至51%至89%。在存在胆脂瘤的情况下，OD的几率为88%。在存在胆脂瘤的情况下，ABG改变OD概率的能力不显著。
低频时ABG狭窄提示无OD。高频时ABG增宽提示存在OD。对于通过纯音听力测定评估OD可能性较小的患者可进行单纯鼓室成形术，而对于OD可能性较大的患者建议进行听骨链的强制性探查及可能的重建。存在胆脂瘤需要进行听骨链探查。
