椎动脉V2段与周围结构关系的解剖学观察

目的 了解椎动脉V2段与周围结构的解剖关系，探讨颅外椎动脉供血不足的解剖学机制。方法 在20例头部尸体标本，解剖观察椎动脉与周围结构的关系；其中17例制成干骨，测量C3－C7有关横突孔参数。另在2例新鲜尸体标本取材行组织学切片观察椎动脉周围组织。结果 延续自颈椎、横突孔、关节突等骨膜组织形成明显的纤维鞘膜样结构，将椎动脉、椎静脉及神经根包裹在内。椎动脉外膜与钩突之间有纤维这样组织相连，限制椎动脉。横突孔内未见明显骨性狭窄。结论 椎动脉周围的骨性吸软组织性因素对椎动脉起到限制固定作用，在颈椎运动或不稳时，椎动脉易受波及而出现供血不足。椎动脉牵系机制在椎动脉供血不足发生中可能起着重要的作用。

Anatomical observation on relationship of the second segment of vertebral artery (V2) with its surrounding structures

Objective To explicit the anatomical mechanism of extracerebral vertebral artery insufficiency on the basis of studying the relationship of the second segment of vertebral artery (V2) with its surrounding structures.Methods Twenty preserved head neck specimens were used to observe V2 and its relation to surrounding structures macroscopically.Among them,seventeen were made into dry cervical vertebrae including C3 C7.and transverse foramens were measured.Another two fresh cadavers were used to observe the surrounding structures of vertebral artery microscopically.Results The fibrous sheath like structures derived from periosteal tissues of cervical vertebra,transverse process and uncus process were observed to enwrap vertebral artery,vein and spinal nerve root.The V2 vertebral artery was fixed by the fibrous tissue connecting vertebral artery adventitia to uncus.No obvious transverse foramen narrowing was found during this specimen observation.Conclusion The vertebral artery is fixed and tethered by its surrounding structures including bony and soft tissues.The vertebral artery is susceptible to be affected in case of cervical motion or instability.The tethering mechanism of vertebral artery may play an important role in the etiology of vertebral artery insufficiency.