Mechanical Thrombectomy Using a Stent Retriever with an Intermediate Catheter for Partially Occluded Middle Cerebral Artery Fenestration

Abstract

Middle cerebral artery (MCA) fenestration is a rare vascular variant of the MCA. When this occlusion occurs, it presents challenges to identification and recanalization. We describe a patient with a partially occluded MCA fenestration in whom recanalization was successfully achieved via mechanical thrombectomy using a stent retriever with an intermediate catheter. A 65-year-old man with a history of ischemic stroke and homocysteinemia presented with dysarthria and expressive aphasia 14 hours after symptom onset. National Institutes of Health Stroke Scale score was 12/42. Noncontrast computed tomography scan revealed encephalomalacia in the left cerebral hemisphere. Catheter angiography displayed a left internal carotid artery orifice and M1 segment subocclusion. The primary diagnosis was acute ischemic stroke. Mechanical thrombectomy was performed by passing a stent retriever through the subtotal occlusive segment of the left MCA. After angiography was completed, reperfusion was considered successful, with a modified Thrombolysis in Cerebral Infarction grade 3. The fenestration was discovered in the middle to distal part of the left MCA M1 segment where the thrombus was located. After 3 days, magnetic resonance imaging showed much ischemic damage to the left hemicerebrum area. The day after endovascular treatment, the patient's neurologic deficit recovered to its pre-onset state. At 6-months follow-up, stroke had not recurred, and the patient is living independently with a modified Rankin scale score of1. Mechanical thrombectomy may be feasible and safe in MCA fenestration occlusion.