![]() ![]() The branch then passes through a commonly enlarged hypoglossal canal and joins to an ipsilateral inferior segment of the basilar or vertebral artery. The anastomosis typically originates between the C1 and C2 levels of the internal carotid artery. If there is a persistent fetal hypoglossal artery, Brismar’s diagnostic criteria suggest that an extracranial branch should originate from the internal carotid artery and anastomose with the vertebrobasilar trunk after passing through the hypoglossal canal. Less common anastomoses involve the otic and proatlantal arteries. The most frequent of these anastomoses originates from a persistent fetal trigeminal artery. This variation is more common on the left side and in females. Knowledge of these persistent fetal anastomoses is crucial as they can contribute significant blood flow to the vertebrobasilar system and posterior cerebral circulation.Ī persistent fetal hypoglossal artery is the second most common anastomosis between the carotid and vertebrobasilar arterial systems ( Figs. All other reported cases have identified this variation using magnetic resonance or computed tomography angiography. To our knowledge, our case is the first cadaveric report. Only 10 cases of this uncommon variation can be found in the literature. An anastomosis was identified between the external carotid and vertebral arteries via a hypoglossal branch of the ascending pharyngeal artery. These variations, which typically connect the internal carotid artery to the vertebral artery, are estimated to occur in 0.027% to 0.26% of the population. Fetal trigeminal arteries are most likely to persist followed by hypoglossal, otic, and proatlantal intersegmental arteries ( Fig. Persistent fetal, or primitive, anastomoses between the carotid and vertebrobasilar systems are known variations resulting from a failure of regression during embryogenesis. ![]()
0 Comments
Leave a Reply. |