Jt. Jerius et al., VERTEBROBASILAR SYNDROME-ASSOCIATED WITH SUBCLAVIAN ORIGIN OF THE RIGHT INTERNAL CAROTID-ARTERY, Journal of vascular surgery, 21(5), 1995, pp. 855-861
A case of absence of the right common carotid artery with origin of th
e external carotid artery from the innominate artery and origin of the
internal carotid artery from the right subclavian artery proximal to
the right vertebral artery is presented. Atherosclerotic occlusion at
the origin of the right subclavian artery and occlusion of the left in
ternal carotid artery resulted in a vertebrobasilar syndrome. Blood fl
ow from the right external carotid reconstituted the right vertebral a
rtery via muscular collateral vessels, moving first retrograde to the
subclavian artery and then antegrade through the right internal caroti
d artery. Symptoms were successfully relieved by transposition of the
internal carotid to the external carotid artery. This is the second re
ported case in the literature and the first to be observed in a clinic
al setting. The anomaly can easily be explained by embryonic persisten
ce of the right ductus caroticus associated with involution of the rig
ht third aortic arch.