内窥镜辅助下乙状窦前后锁孔手术入路的应用解剖

目的：为内窥镜在锁孔手术中的应用提供参考。方法：在15例30侧10％甲醛溶液固定国人成人尸头上，模拟乙状窦前入路操作，在其中5例10侧标本上同时模拟乙状窦后入路操作，内窥镜下操作并观察颅内结构。比较两种不同入路的观察范围与影响内窥镜操作因素。测量乙状窦前缘中点、乙状窦后缘中点与颅内固定标志间距离等相关数据。结果：乙状窦前方的解剖学变异较多，对乙状窦前入路影响较大。乙状窦后入路受解剖学变异的影响较小。乙状窦前缘中点、乙状窦后缘中点与颅内同一固定标志距离存在明显的差异。结论：乙状窦前入路操作距离短，无需牵拉小脑，内窥镜可到达桥小脑角，并观察到脑干腹侧结构，但入路复杂，内窥镜操作受解剖结构影响大；乙状窦后入路简单易于掌握，需要一定的小脑牵拉，在内窥镜的辅助下可以全面了解桥小脑角结构，但对脑干腹侧的结构观察欠佳。

Applied Anatomy of Two Kinds of Keyhole Approach Assisted by Endoscopy

Objective:To provide anatomic data of keyhole approaches for the endoscope-assisted operations. Methods:The operations via presigmoid approaches were simulated on 15 cadaveric specimens under endoscopy.At the same time, the operations by retrosigmoid approaches were performed on 5 cadaveric specimens. To observe intracranial structures and compare the visual fields and factors that impact on endoscope operating.To detect data such as working distances from the midpoints of anterior and posterior edges of sigmoid sinus to the intracranial permanent marks.Results: The operations via retrolabyrinthine approaches were even more influenced by the anatomic variation in front of sigmoid sinus than via retrosigmoid approaches. The distances from the midpoints of anterior and posterior edges of sigmoid sinus to the same intracranial permanent marks were obviously different. Conclusions:During the operation via retrolabyrinthine approach, the working distance is shorter, the endoscope could reach the cerebellopontine angle,the anterior and lateral aspects of brain stem could be observed without dragging cerebellum. But this operative approach is complex and even more influenced by anatomic variation. On contrast, the operation via retrosigmoid approach is simple and easy to control. The cerebellopontine structures can be fully observed with help of endoscope via retrosigmoid approach with cerebellar retraction.