乙状窦后入路的应用解剖学研究

目的　为乙状窦后入路手术提供解剖学依据。方法　对 2 0个成人颅骨标本乙状窦后入路手术骨窗的确定、开窗范围的大小进行观测。 15个成人尸头乙状窦后入路开窗显露桥小脑三角区域的结构 ,测量骨窗至三叉神经、面神经、前庭蜗神经、舌咽神经和小脑下前动脉袢的距离。结果　顶切迹至乳突尖连线中点向后 2 6 38± 3 95mm作为骨窗的中点 ,以该点为圆心 ,画出半径为 2 0mm的圆 ,该圆形区域与乙状窦不重叠。骨窗至三叉神经、面神经、前庭神经、舌咽神经穿硬脑膜和小脑下前动脉袢处的距离分别为 5 6 6 3± 4 5 5mm、4 7 2 3± 3 6 9mm、4 5 91± 3 99mm、4 3 73± 4 0 1mm、4 5 95± 3 77mm。结论　顶切迹至乳突尖连线中点向后2 6 38± 3 95mm处为乙状窦后入路手术开放骨窗的中点 ,骨窗的大小控制在半径为 2 0mm的圆形区内较为理想 ,手术中应注意保护桥小脑三角区域的有关结构。

Applied Anatomic Study of Retrosigmoidal Approach

Objective To provide the anatomic data for the operations through retrosigmoid approach. Methods 20 adult skull specimens were observed to define the location and region of bony window in the operations by gross anatomical method. Simulated operations were performed On 15 dry adult head specimens and the structures of cerebellopontine angle were exposed, then the distances from the bony window to trigeminal nerve, facial nerve, vestibulocochlear nerve, glossopharyngeal nerve and anterior inferior cerebellar artery loop were measured by gross anatomica method. Results The bony window, which does not overlap with sigmoid sinus, was a circle with a radius of 20mm, whose center located behind the midpoint of the line from parietal notch to mastoid apex with a distance of 26.38±3.95mm. The distances between bony window and the spots of cerebral dura mater through which trigeminal nerve, facial nerve, vestibulocochlear nerve, glossopharyngeal nerve traversed, and the distance from bony mindow to anterior inferior cerebellar artery loop were 56.63±4.55mm, 47.23±3.69mm, 45.91±3.99mm,43,73± 4.01 mm, 45.95±3.77mm respectively. Conclusion The above method of locating bony window through retrosigmoid approach is ideal and feasible, the structures in cerebellopontine angle should be protected when the operations are being performed.