RESUMO
M1 fenestration of the middle cerebral artery is rare. We present two patterns of acute thromboembolic conditions in M1 fenestrations treated with mechanical thrombectomy. Case 1 was a male in his 60s presenting with right hemiparesis and aphasia. Angiography showed acute left M1 proximal occlusion; the first direct aspiration revealed two parallel routes, and the second aspiration achieved complete recanalization of the left M1 fenestration. Case 2 was a male in his 70s presenting right hemiparesis and aphasia. Angiography revealed a sudden stair-like narrowing of the left M1 in the intermediate part, and a retrograde blood flow cavity was observed on the upper side of the distal part. Mechanical thrombectomy was performed to diagnose the upper limb occlusion of the left M1 fenestration, and successful recanalization was achieved through direct aspiration. Anatomical variations, such as fenestration, should be considered to reduce complication risks.
RESUMO
The authors report an anomalous fenestration at the M1 portion of the middle cerebral artery found incidentally in a patient affected with a ruptured aneurysm at the ipsilateral internal carotid artery(ICA) and unruptured small aneurysms at the contralateral P1 and ICA. The anomaly was confirmed both angiographically and intraoperatively. A review of the literature indicated several reports of this same anomaly, many of which were associated with aneurysms involving either the proximal end of the fenestration or other cerebral arteries. In the interpretation of cerebral angiograms and during intracranial operations, clinical attention should be paid to this rare anomaly.