颅后窝三角显微解剖及临床意义

目的：研究颅后窝三角的显微特征，为颅后窝手术提供快速辨认神经、血管的方法。方法：旁正中切口、乙状窦后入路，逐层开颅并切开硬脑膜，显微观察12具成人头部标本硬脑膜形成的三角。结果：颅后窝硬脑膜皱襞反光形成一个三角形：外上顶点即“光点”，位于横窦与乙状窦移行处的前方；内上顶点恰是岩静脉注入岩上窦的位置；颈静脉孔构成颅后窝三角内下顶点。结论：手术显微镜下，颅后窝硬脑膜形成的标志性三角，可以帮助迅速辨认三叉神经、岩静脉，经过内耳门的面神经、前庭蜗神经以及经过颈静脉孔的舌咽神经、迷走神经、副神经。

Microsurgical anatomy and clinical significance of the trigone in posterior cranial fossa

Objective: To study the features of dura in posterior cranial fossa and provide methods to identify quickly the trigeminal nerve , pretrosal vein, internal acoustic port, facial nerve, vestibulocochlear nerve, jugular foramen, glossopharyngeal nerve, vagus, accessory nerve during operating on posterior cranial fossa. Methods: 12 formalin-fixed human adult cadaveric head (24 sides) were examined after the cranial arteries were injected with red emulsion . By the approaches of post sigmoid sinus, observing the dura, the trigeminal nerve, pretrosal vein, internal acoustic port, facial nerve ,vestibulocochlear nerve, jugular foramen, glossopharyngeal nerve ,vagus ,accessory nerve in posterior cranial fossa under operating microscope. Results: The dura in posterior cranial fossa formed a trigone under operating microscope which possessing 3 summits and 3 edges. The extra-superior summit was light-spot, located at the front of the transition of transverse sinus and sigmoid sinus. The inter-superior summit was pretrosal vein and trigeminal nerve. Linking the two summits constituted the superior edge. The inter-inferior summit was jugular foramen, glossopharyngeal nerve ,vagus and accessory nerve , and the linking-line between the inter-superior summit and the inter-inferior summit was medial edge.The lateral edge was just the line through external aperture of aqueduct of vestibule from the light-spot to the inter-inferior summit. The internal acoustic port of facial nerve and vestibulocochlear nerve was located nearly the middle of medial edge inside the triangle. Conclusions: The dura in posterior cranial fossa forms a characteristic mark trigone under operating microscope. According to this trigone, we can quikly find what we want during operation in posterior cranial fossa.