title: Aneurysm rupture at an anomalous collateral artery that extended from the proximal A2 segment to the middle of the M1 segment, bypassing atresia of the internal carotid artery bifurcation. Case report.
abstract: The authors report the first known case in which an anomalous collateral artery was found to connect the proximal A2 segment with the middle of the M1 segment. This rarity was associated with atresia of the T-shaped internal carotid artery bifurcation. Two aneurysms had developed on a tortuous and tangled portion of the anomalous artery; one of them had ruptured, producing a subarachnoid hemorrhage and an intracerebral hematoma in the area of the putamen. The aneurysms were clipped and the intracerebral hematoma was removed via an emergency craniotomy. Possible causes of the anomaly and the differences between it and accessory and duplicated middle cerebral arteries are reviewed.
authors.affiliation: Department of Neurosurgery, Kyungpook National University, Daegu, Republic of Korea. jparkmd@hotmail.com
authors.forename: Jaechan
authors.initials: J
authors.lastname: Park
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Hwang
authors.forename: In Suk
authors.initials: IS
authors.lastname: Hamm
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging* / Q000601:surgery; D018376:Cardiovascular Abnormalities / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D002533:Cerebral Angiography; D003097:Collateral Circulation; D003399:Craniotomy; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D020768:Middle Cerebral Artery; D012422:Rupture, Spontaneous