不同程度的阻断内耳供血对耳蜗微循环和耳蜗生理功能的影响

目的：观察不同程度的阻断豚鼠内耳供血对耳蜗微循环和耳蜗生理功能的影响。方法：手术压迫基底动脉的分支小脑前下、后下动脉、观察耳蜗餐侧壁微循环改变，测量脑干诱发电位（ＡＢＲ）幅度变化。结果：耳蜗血流轻、中度下降时ＡＢＲ幅度无明显变化。耳蜗血流重度下降时ＡＢＲ幅度下降；耳蜗供血下降对耳蜗外侧壁血管纹毛细血管血流影响大，当其血流停止后，耳蜗生理功能依赖于螺旋韧带血管血流。结论：耳蜗供血理明显大于一般情况下

Effects of cochlear ischemia at different levels on the cochlear microcirculation and the cochlear functions

Objective:To examine the effects of cochlear ischemia at different levels on the cochlear microcirculation and the cochlear functions in guinea pigs.Methods:Anterior inferior cerebellar artery and the posterior inferior cerebellar artery were compressed with various pressures. The microcirculations in the cochlear lateral wall were observed and the amplitudes of brain stem response (ABR) were measured during and after the arterial occlusion. Results:ABR amplitudes were kept constantly if cochlear blood flow changes were mirror or moderate. However, if the blood flow decreased markedly, the ABR amplitudes decreased or even totally abolished. The decreased volume of the blood flow to the cochlea affected the blood flow more dramatically in the vessels of the stria vescularis than that in the spiral ligament. When the blood flow in these vessels stopped, the amplitude changes of ABR were largely associated with blood flow in the vessels of the spiral ligament. Conclusion:The potential capacity of blood flow to the cochlea exceeds the actual requirement of the cochlea to maintain its normal function. When the blood flow to the cochlea severely decreases, keeping the blood flow in thd vessels of the spiral ligament is crucially important in maintaining the cochlear functions.