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Unilateral segmental agenesis of the vertebral artery at the C2 level
Philippe Gailloud1, Ayushi Gautam2, Justin Caplan3
1Division of Interventional Neuroradiology, The Johns Hopkins Hospital, 1800 E Orleans Street, Baltimore, MD, 21287, USA. phg@jhmi.edu.
Purpose:
To report a case of unilateral segmental agenesis of the vertebral artery (VA).
Methods:
We describe the angiographic and MRI features of a segmental VA agenesis (C2 segment).
Results:
VA agenesis is caused by the absence of the anastomotic connection normally linking two adjacent intersegmental arteries; in the reported observation, a paravertebral extraforaminal anastomosis replaced the C2 segment normally joining the 1st and 2nd cervical intersegmental arteries through the C2 transverse foramen.
Conclusion:
We present an observation of segmental VA agenesis. This variant is consistent with the developmental history of the VA. It appears exceptional but is more likely underappreciated.
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