Abstract
Intracranial aneurysms generally produce neurological deficit by means of hemorrhage, vasospasm or mass effect. Aneurysms as a suspected source of emboli have rarely been reported in the literature. On the other hand, the operative management of large and giant aneurysms is complicated by their atheromatous and thick walls, frequent intramural thrombosis with calcification, and broad-based necks. We describe a case of a 63-year-old woman in whom a partially thrombosed large aneurysm of the right middle cerebral artery (MCA) was the source of emboli resulting in transient ischemic attacks (TIAs). In this report, the usefulness of endaneurysmal microendarterectomy for direct obliteration of the large aneurysm with a hard, calcified atheroma at its base is particularly emphasized.
A 63-year-old woman was admitted with a history of several episodes of left arm weakness that cleared within 5 minutes. A neurological examination showed unstableness in one leg standing, but no other abnormalities. Physical examination and routine laboratory data were normal. A CT scan revealed a large high-density mass in the right sylvian fissure. A MRI demonstrated a 2-cm right sylvian mass indicative of a partially thrombosed large aneurysm. Right carotid angiography showed a 7 mm aneurysm at the bifurcation of the MCA and occlusion of the prerolandic artery. There were no other abnormal angiographic findings.
A right frontotemporal craniotomy was performed. The right carotid cistern was opened and the proximal internal carotid artery was obtained. The right sylvian fissure was subsequently dissected and opened. Proximal and distal control of the MCA and its branches was obtained. The neck and base of the aneurysm were then circumferentially exposed. A calcified atheroma at the aneurysm base prevented clip placement without compromise of the parent artery. Once the temporary clips were in place, the dome of the aneurysm was transected. Intramural thrombectomy was performed with an ultrasonic aspirator. By grasping the thickened aneurysm wall, a cleavage plane between the atheroma and the aneurysm wall with a microdissector was developed. Thereafter, endaneurysmal microendarterectomy was completed. Removal of the atheroma allowed complete obliteration of the aneurysm neck with Sugita clips (#15 and #18). Local circulation was restored after 22 minutes of occlusion. The patient had an uneventful postoperative course and suffered no further TIAs.
Temporary trapping of the aneurysm, intramural thrombectomy, and endaneurysmal microendarterectomy allow direct obliteration of the aneurysm neck with preservation of the parent artery.
