Anomalous vertebral arteries in Klippel-Feil syndrome with occipitalized atlas: CT angiography

Society for Cardiovascular Magnetic Resonance 2020 Case of the Week series

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). Case of the week is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. Each case consists of the clinical presentation and a discussion of the condition and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2020 Case of the Week series of 11 cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar search engine.

CT angiographic evaluation of the V3 vertebral artery course in cases of occipitalized atlas, a study of 25 cases

OBJECTIVES

To study the relationship of the 3rd segment of the vertebral artery to the posterior arch of the atlas in patients with occipitalized atlas, using CT angiography.

METHODS

A retrospective study of 25 cases with complete or partially occipitalized atlas who underwent CT angiography evaluation. Fifty vertebral arteries were analyzed in relation to the respective/related half of the posterior arch of the atlas.

RESULTS

Out of 50 vertebral arteries, 35 (70%) were anomalous; 31 (62%) traversed though bony canal between the fused occiput and atlas, and 4 (8%) coursed between C1 and C2 (C2 segmental type of vertebral artery). Except one, all anomalous vertebral arteries were associated with a fused corresponding side of posterior arch of atlas.

CONCLUSION

The V3 portion of the vertebral artery assumes an anomalous course at the craniovertebral junction in most cases of occipitalized atlas, and this is strongly determined by the fusion status of the posterior arch of the atlas. Aberrations in its course are still seen despite expectations based on this fusion status. Preprocedural CT Angiography provides accurate information of its course to prevent iatrogenic VA injuries.

ADVANCES IN KNOWLEDGE

CT Angiography should be performed before any procedures at the craniovertebral junction in cases of occipitalized atlas to prevent iatrogenic, potentially catastrophic injuries to vertebral artery due to its anomalous course in most of these cases. There are very few such studies in the literature, none in radiology literature. We also describe some rare cases, including a case never described in any literature.

Klippel–Feil Syndrome with Multiple Cervical Anomalies Discovered Following Trauma

The approach to the upper cervical spine is a challenge for surgeons, not only for its complex anatomy but also for the great variety of pathologies. Klippel–Feil syndrome (KFS) is a congenital disease characterized by the fusion of two or more cervical segments and is associated with various musculoskeletal and vascular malformations. However, there is no consensus on the type of surgery, approach, level of fixation or fusion. We report the case of a KFS, associated with multiple anatomical variants, who suffered a traumatic cervical injury and underwent surgical treatment.

Anomalous vasculature in the neck diagnosed by ultrasound

Anomalous vascular anatomy was detected in the neck of a 52-year-old female with a Klippel-Feil anomaly. Ultrasound identified three separate arteries in the left carotid sheath without any branching or bifurcations. The vascular waveforms were used to identify the vessels as the internal carotid artery, external carotid artery and vertebral artery. This rare vascular anomaly was confirmed with CT angiography.