摘要： 目的 观察先天性寰枕融合患者椎动脉走行的解剖学特征及其在颅颈交界区后路内固定手术中的临床意义。方法 回顾自2007 年1 月-2010 年10 月施行CT 血管造影检查的48 例先天性寰枕融合患者诊断与治疗经过，观察分析其椎动脉解剖走行特点。结果 根据椎动脉分支和行程，48 例患者96 侧椎动脉共分为5 种类型：Ⅰ型，椎动脉单干，走行于枕骨化的寰椎后弓和枢椎椎板之间，共19 侧（19.79%）；Ⅱ型，椎动脉单干，走行于寰椎与枕骨之间的骨孔，共43 侧（44.79%）；Ⅲ型，椎动脉单干，走行于枕骨与寰椎后弓之间，共29 侧（30.21%）；Ⅳ型，椎动脉开窗，一支走行于枕骨化的寰椎后弓下方，一支走行于寰椎和枕骨之间，入硬脑膜后重新汇合成椎动脉，共3 侧（3.13%）；Ⅴ型，椎动脉发育细小或缺如，共2 侧（2.08%）。结论 先天性寰枕融合患者，椎动脉解剖走行变异较大。对于Ⅰ型和Ⅳ型椎动脉患者，神经外科手术显露时损伤椎动脉的风险较高；而Ⅱ型和Ⅲ型椎动脉患者，遵守严格的骨膜下分离操作原则可降低椎动脉损伤风险。手术前行CT 血管造影并结合骨性结构融合特点，能够明显降低手术损伤的风险。

关键词: 寰枕关节, 脱位, 椎动脉, 血管造影术

Abstract: Objective To study the anatomical variation of vertebral artery (VA) at the craniovertebral junction (CVJ) in patients with occipitalization of the atlas. Methods Through reviewing the image studies of 48 patients with occipitalization of the atlas admitted to Department of Neurosurgery, Xuanwu Hospital from January 2007 to October 2010, the anatomical characteristics of VA were studied retrospectively. Results According to the branches and anatomical course of VA, 48 patients (96 sides) were divided into 5 types. Type 1: the VA is single trunk, running between the occipitalized atlantal posterior arch and axial plate (19 sides, 19.79%); type 2: single trunk VA runs through a bony canal between the assimilated atlas and occipital cranium (43 sides, 44.79% ); type 3: single trunk VA runs between the normal occipital cranium and atlantal posterior arch (29 sides, 30.21% ); type 4: VA has a fenestration, with one branch running below the occipitalized atlantal posterior arch and the other branch running above the atlantal posterior arch (3 sides, 3.13%), 2 branches merge as one VA trunk after entering into the dura; type 5: hypogenesis or agenesis of VA (2 sides, 2.08% ). Conclusion The vertebral artery has a high rate of anatomical variation in patients with assimilation of the atlas. The risk to be injured is high for type 1 and type 4 variations during surgical dissection. For type 2 and type 3, careful subperiosteal dissection can decrease the risk. Preoperative computed tomography (CT) angiography combined with bone reconstruction can provide important information in the preoperative evaluation, thus decrease surgical risk.

Key words: Atlanto-occipital joint, Dislocations, Vertebral artery, Angio