A case of middle cerebral artery occlusion with repeated reocclusion during mechanical thrombectomy diagnosed pathologically with iatrogenic cerebral arterial dissection.

Abstract

An eighty-seven-year-old woman presenting with disturbance of consciousness and right hemiplegia was transported to our institution. Head CT and CT angiography revealed acute ischemic stroke due to occlusion of the left middle cerebral artery (MCA). To recanalize the occlusion, mechanical thrombectomy after intravenous tissue plasminogen activator was performed. A horizonal segment of the left MCA (M1) was recanalized after one pass with a stent retriever and an aspiration catheter, but an insular segment of the left MCA (M2) was difficult to recanalize because of repeated reocclusion during the procedure. Her left M2 could not be sufficiently recanalized after a total of three passes with the stent retriever. Her left cerebral hemisphere showed extensive infarction, diagnosed by postoperative CT. Despite medical treatment, she died on day 4 from brain herniation. Pathological autopsy revealed severe arteriosclerotic changes in multiple intracranial arteries and coexistence of atheromatous plaque and arterial dissection in the distal left M1. The mechanism of dissection was regarded as iatrogenic dissection due to the use of the stent retriever for vessels with severe arteriosclerosis. We should keep in mind iatrogenic cerebral arterial dissection if occluded vessels repeated reocclusion during mechanical thrombectomy, especially in aged stroke patients, which is severe arteriosclerosis.