Anomalous atlantoaxial portions of vertebral and posterior inferior cerebellar arteries

Abstract

In a review of the vertebral angiograms of 300 patients free from disease at the craniovertebral junction, we found atlantoaxial arterial anomalies in 2,3%. These were: 2 cases in which the vertebral artery ran in the spinal canal below C1, 3 cases of duplication of the vertebral artery above and below C1, and 2 cases of origin of the posterior inferior cerebellar artery at C2. Although these arteries ran in the spinal canal between C1 and C2, they never encroached upon the posterior third of the canal. From the survey of another 21 patients having bony abnormalities at the craniovertebral junction, the first type of arterial anomaly described above was seen in 4 patients and associated with failure of segmentation of the embryonic sclerotome such as occipitalization of the atlas or Klippel-Feil syndrome. It is possible to relate the development of these anomalous vessels to malarrangement of the embryonic segmental arteries. Our results indicate that one must be cautious with lateral C1/2 puncture or surgical exposure of the region.

A case of vertebral artery duplication at the level of atlas: anatomical description

“…Such atypical development may be accidental, but may have also complex genetic basis, as such variations in the vertebral artery course are more frequently seen in patients with Down syndrome examined because of atlanto-axial subluxation [12]. To our best knowledge, there are only two cases of vertebral artery passing between the atlas and axis together with the C2 spinal nerve described in contemporary literature and verified by anatomical dissection [7,13,14]. In these cases vertebral artery pierced the dura below the level of atlas vertebra, but the C1 transversary foramen and suboccipital space contained no artery.…”

“…There is significant number of papers discussing fenestrations and duplications of the vertebral artery based on angiographic imaging examinations [4][5][6][7][8][9]. Lasjaunias [5,10] basing on his experience with classic angiography in numerous anatomical variants and abnormalities and earlier embryological studies of Padget [11], proposed a schematic 'grid' model explaining embryology of normal and abnormal vertebro-basilar system.…”

Posterior Atlantoaxial Screw-Rod Fixation in a Case of Aberrant Vertebral Artery Course Combined with Bilateral High-Riding Vertebral Artery

“…In the Sato et al 11) and Tokuda et al 14) angiographic series, only 0.7% of the VAs coursed under the C1 posterior arch in patients without an osseous anomaly; whereas, the incidence of this VA anomaly went up to 19.7% in those with osseous anomalies such as the occipitalization of C1 or Klippel-Feil syndrome.…”

“…An aberrant vertebral artery (VA) coursing below the posterior arch of C1 which does not pass through the C1 transverse foramen has rarely been reported in the literature (Table 1) 1, 4,5,7,[12][13][14]16) . In the Sato et al 11) and Tokuda et al 14) angiographic series, only 0.7% of the VAs coursed under the C1 posterior arch in patients without an osseous anomaly; whereas, the incidence of this VA anomaly went up to 19.7% in those with osseous anomalies such as the occipitalization of C1 or Klippel-Feil syndrome.…”

Surgical Considerations of Rheumatoid Disease Involving the Craniocervical Junction and Atlantoaxial Vertebrae

“…The left vertebral artery is deemed dominant in 35% of patients, whereas the right side is dominant in 23%. Equivalent vertebral arteries are present in 41% of cases (Menendez & Wright 2007, Tokuda et al 1985. .…”