标准翼点硬脑膜外入路显露眶上裂的显微解剖

目的在标准翼点硬脑膜外入路显露眶上裂区时描述眶上裂内容物的空间关系,为该区域肿瘤的手术治疗提供依据。方法在15例经过防腐处理的尸头标本中,实施了30侧标准翼点硬脑膜外入路。经该入路解剖分离出眶上裂及其内容物分为五个连续步骤。在放大5～25倍显微镜下对眶上裂区的分区、硬膜结构特征及海绵窦的前部进行逐层显微解剖、观察、测量及分析。结果笔者建议的连续五个操作步骤可很好地显露眶上裂及其周围区域。通过切断连接硬脑膜和眶骨膜的硬膜索带松解额颞叶,减少了对脑组织的牵拉。从颞极硬膜索带外侧缘到眶上裂神经血管共同鞘的距离为(5.52±1.09)mm。可以通过两种方法切开Zinn腱环暴露眶上裂的中央区。结论在标准翼点硬脑膜外入路过程中熟悉眶上裂内容物的三维关系可使得神经外科医生能够安全地到达该区域。翻开圆孔硬脑膜返折较卵圆孔处容易。切开颞极硬膜索带时应注意避免损伤泪腺神经。眶上裂的显微解剖有利于在处理切开总腱环时保护颅神经。

Microsurgical Anatomy of Superior Orbital Fissure Exposed by a Standard Pterional Epidural Approach

Objective To describe the spatial relationships of the contents of the SOF,suggest a specific sequence of steps for exposing the SOF region in a pterional epidural approach,and to verify practical significance of microanatomy in this region.Methods Using standard microsurgical equipment and instruments,the authors performed 30 standard pterional epidural approaches in 15 embalmed cadaver heads in which the vascular systems had been injected with colored material under the microscope(magnification,5 ～ 25 times).Five sequential steps were delineated for approaching and dissecting the SOF and its contents.Results The proposed sequence of steps allowed a controlled exposure of the SOF and surrounding areas.Untethering the frontotemporal lobe by transecting the dural bridge connecting the dura to the periorbita allowed good exposure of the basal frontotemporal lobes,both intra-and extradurally,and reduced brain retraction.The distance from the temporal tip dural fold to the nerve-vascular common sheath of SOF was(5.52 ± 1.09) mm.Conclusion Knowing the 3D relationships of the contents of the SOF encountered in the standard pterional epidural approach enables safe neurosurgical access to the area.The dura incision along the surface of V2 at foramen rotundum is easier than the one along the surface of V3 at foramen ovale.Microanatomy of superior orbital fissure is advantageous to protect cranial nerves during incising annulus of Zinn.