乳突开放术后自体骨粉填塞重建外耳道后壁的临床观察

Mastoid obliteration using autologous bone pate for reconstruction of posterior wall of external auditory meatus after mastoidectomy

目的 观察自体乳突皮质骨粉行乳突填塞重建外耳道后壁的临床疗效。方法 43例慢性化脓性中耳炎或中耳胆脂瘤患者行乳突开放＋鼓室成形术后,应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,加耳甲腔成形术。结果 术后随访时间3~22个月,平均13.4个月;所有病例均干耳,术后干耳时间为20-56 d,平均为31.7 d。言语频率（0.5、1、2 k Hz）平均纯音听力（pure tone average,PTA）气导由术前55.0±6.2 d B提高到术后34.0±3.2 d B,骨导由术前28.1±4.4 d B提高到术后21.5±4.1 d B,气骨导差（air-bone gap,ABG）由术前26.8±7.8 d B缩小到12.5±4.1 d B,术后听力提高成功率（术后PTA-ABG≤20 d B）为74.4%（32/43例）。除4例出现填塞骨粉感染、散落外,术后所有患者外耳道形态接近正常解剖结构,鼓膜形态正常,无再穿孔及内陷袋形成,外耳道后壁重建成功率为90.7%（39/43例）。结论 中耳乳突开放术后应用自体乳突皮质骨粉填塞乳突术腔行外耳道后壁重建术,是缩小乳突术腔,获得近似正常的外耳道解剖形态结构的有效方法。

Objective To observe the clinical effect on mastoid obliteration with autologous mastoidal bone pate for reconstruction of posterior wall of external auditory meatus. Methods 43 cases of chronic suppurative otitis media or middle ear eholesteatoma underwent canal down mastoidectomy and tympanoplasty. The mastoidal cavity was obliterated with autologous mastoid cortex bone pate. Results Postoperative follow-up time ranged from 3 to 22 months, with an average of 13.4 months. All cases had dry ears after operation, and the dry ear time ranged from 20 to 56 days, with an average of 31.7 days. Pure tone audiometry showed that the air conduction thresholds of speech frequencies （ 0.5, 1, 2 kHz） got improved from preoperative average of （55.0 ± 6.2） dB to postoperative average of （ 34.0 ± 3.2） dB, and the bone conduction thresholds were improved from preoperative average of （28.1 ± 4.4） dB to postoperative average of （21.5 ± 4.1 ） dB. The air-bone gaps （ABG） got closed from preoperative average of （26.8 ±7.8） dB to postoperative average of （ 12.5 ±4.1 ） dB. The success rate of hearing improvement （ postoperative PTA-ABG≤20 dB） was 74.4% （32/43）. Except for infection and scattering of the packed bone pate in 4 cases, the morphology of external auditory canal in the other patients approximated normal anatomic structure, the tympanic membrane got normal morphology withno perforation and retraction pocket formation. The successful rate of the external auditory canal wall reconstruction was 90.7% （ 39/43 ）. Conclusion Mastoid obliteration using autologous mastoid cortex bone pate is an effective method to narrow the mastoid cavity and to obtain approximate normal external auditory canal morphology after canal down mastoidectomy.