兔内听动脉阻断与听觉改变的关系

目的 探讨实验性内听动脉阻断与术后听力改变的关系及术中听觉监控的方法。方法 实验兔乙状窦后进路暴露小脑桥脑角，下压小脑暴露内听道及第Ⅷ神经复合体，分辨出内听动脉，予阻断不同时间，分别行蜗神经直接复合动作电位(DCAP)和畸变产物耳声发射记录(DPOAE)。结果对照组DCAPN1波潜伏期值无明显改变。内耳血供阻断10s和30s组在压迫开始后3min，DCAPN1波潜伏期值均恢复为初始值。内耳血供阻断1min组在压迫开始后3h，DCAPN1波潜伏期值未恢复为初始值假手术组DPOAE幅值无明显改变，内耳血供阻断10s、30s对DPOAE幅值无影响，内耳血供阻断1min使得DPOAE幅值下降结论兔内耳血供阻断1min可能造成兔听觉不可逆损伤。DCAP、DPOAE能有效、持续地监控内耳血供阻断，是耳神经外科手术中实用的听觉监测手段。

Relationship of hearing function after internal auditory artery occlusion in rabbits

Objective To evaluate the hearing function after internal auditory artery occlusion and the effective-ness of intraoperative hearing monitoring. Methods A retro-sigmoid sinus approach was used in rabbits to expose the facial-acoustic nerve complex and the internal auditory artery (IAA) . The IAAs were occluded for different times, and the direct compound action potentials (DCAP) of the cochlear nerve and distortion product otoacoustic emission (DPOAE ) were recorded. Results The latencies of DCAPN1 were stable in the control group. In the IAA occlusion groups with 10 seconds or 30 seconds, the latencies could return to their primary levels after 3 mi-nutes. Occlusion of IAA for 10 seconds or 30 seconds had no influence in DPOAEs, but with 1 minute occlusion, the amplitude of DPOAEs decreased permanently. Conclusion Occlusion of the inner ear blood supply for 1 minute would probably lead to irreversible damage of the hearing function in rabbits. The DCAP and DPOAE could reflect the inner ear blood supply occlusion effectively and continuously. They are useful hearing monitoring techniques dur-ing otoneurosurgical procedures .