title: [A case report of hypoplasia of the root portion and the intermediate portion of the left internal carotid artery associated with an unusual primitive collateral circulation between the left internal carotid artery and the left external carotid artery].
abstract: The internal carotid artery is one of the most stable arteries and its absence is very rare. We reported a case of hypoplasia of the root portion and the intermediate portion of the left internal carotid artery associated with an usual primitive collateral circulation between the left internal carotid artery and the left external carotid artery. A 57-year-old male developed right hemiparesis of sudden onset 3 days prior to admission. On admission, right hemiparesis and right minimal facial palsy was observed. The left direct carotid angiogram revealed that the root portion and the intermediate portion of the left internal carotid artery were hypoplastic. There was an unusual primitive collateral circulation between the left internal carotid artery and the left external carotid artery. From an embryological point of view, normally, the internal carotid artery is derived from the third aortic arch and the dorsal aorta when the embryo is attained the 3-mm stage. The root portion of the internal carotid artery is formed from the third aortic arch. The dorsal aorta between the third and the first aortic arch form the intermediate portion. The distal part of the internal carotid artery originates from the dorsal end of the first aortic arch. The common carotid artery begins to form in the 12-mm to 14-mm embryo, following involution of portion of the ventral aortic root between the third and the fourth aortic arch. The external carotid artery arises from the aortic sac and migrate up to the third aortic arch.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Neurosurgery, Nagai Municipal General Hospital, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Shiina
authors.forename: Y
authors.initials: Y
authors.lastname: Sakuta
mesh_terms: D001013:Aorta, Thoracic / Q000002:abnormalities; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology*; D002343:Carotid Artery, Internal / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000196:embryology; D002533:Cerebral Angiography; D003097:Collateral Circulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed