Tubbs R Shane, Salter E George, Oakes W Jerry
Department of Cell Biology, University of Alabama at Birmingham, and Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama, USA.
J Neurosurg Spine. 2006 Apr;4(4):319-22. doi: 10.3171/spi.2006.4.4.319.
An anomalous vertebral artery (VA) position can jeopardize an otherwise successful procedure, such as a posterior cranial fossa decompression for hindbrain herniation, and may increase the propensity for VA occlusion.
The authors describe the detailed anatomy of the entrance site of the VA in adult human crania in which there is occipitalization of the atlas. They found that if the atlantal posterior arch or hemiarch was fused to the occiput one should anticipate encountering an anomalous osseous pathway as the VA enters into the cranium, as evidenced by this finding in 80% of their specimens. An anomalous entry pathway was present in all but one left-sided specimen in which the left posterior hemiarch was not fused to the occiput and one right-sided specimen in which there was an unfused and rudimentary posterior arch of the atlas.
The clinician should consider the possibility that the VA takes anomalous routes into the skull in cases in which there is occipitalization of the atlas.
椎动脉（VA）位置异常可能危及原本成功的手术，如因后脑疝进行的后颅窝减压手术，并且可能增加VA闭塞的倾向。
作者描述了寰椎枕化的成年人类颅骨中VA入口部位的详细解剖结构。他们发现，如果寰椎后弓或半侧弓与枕骨融合，那么当VA进入颅骨时应预期会遇到异常的骨性通道，他们80%的标本中都有这一发现作为证据。除了一个左侧半侧弓未与枕骨融合的左侧标本和一个寰椎后弓未融合且发育不全的右侧标本外，所有标本均存在异常的进入通道。
在存在寰椎枕化的情况下，临床医生应考虑VA进入颅骨走行异常的可能性。
