Thromboembolic Multivessel Occlusion: Stentriever-Assisted Embolectomy for Acute Bilateral MCA Occlusions

“Thromboembolic multivessel occlusion” is defined as concurrent acute occlusions, either within or distant from an involved territory, in patients undergoing endovascular reperfusion therapies. They occur in about 10% of patients subjected to angiography for endovascular stroke treatment and are frequently missed on pre-interventional diagnostic imaging. Occlusion of both middle cerebral arteries (MCAs) or their distal branches is a rare subset of multivessel occlusion, estimated to account for less than 1% of cases of acute ischemic stroke. Patients with acute bilateral MCA occlusion are typically comatose upon arrival at the Emergency Department, and the diagnosis carries an extremely poor prognosis. We present the case of a 75-year-old woman with a past medical history of arterial hypertension, hyperlipidemia, diabetes mellitus type 2, and atrial fibrillation, under occasional treatment with low-molecular-weight heparin, atorvastatin, metformin, angiotensin-converting enzyme (ACE) inhibitors, and diuretics. She was admitted to the Emergency Department due to drowsiness, confusion, speech disturbances, and muscle weakness in four limbs, more pronounced on the right. The patient was last known well 5 h before admission. Her baseline National Institutes of Health Stroke Scale (NIHSS) score was 30. Noncontrast cranial CT revealed early ischemic changes in the left insular cortex and the left posterior temporal area (Alberta Stroke Program Early CT Score [ASPECTS] 8). CT angiography (CTA) confirmed an occlusion of the left MCA in the distal M1 segment. CT perfusion (CTP) demonstrated large areas of hypoperfusion with a sizeable mismatch between the ischemic penumbra and core in both hemispheres. The patient was sedated, intubated, and transferred to the angiography suite for mechanical thrombectomy. Angiography of both internal carotid arteries (ICAs) confirmed occlusion of the left MCA in the distal M1 segment and occlusion of the dominant frontal branch of the right MCA in an M2 segment. The patient underwent successful and uneventful endovascular revascularization of both occlusions. She was extubated 5 h after the intervention, exhibiting significant neurological improvement with a post-procedure NIHSS of 15. Post-procedure cranial CT revealed an ischemic lesion in the region supplied by the left MCA, without signs of hemorrhagic transformation (ASPECTS 5). The patient was discharged after 15 days to a rehabilitation facility with an NIHSS of 13 and an mRS score of 4. Endovascular treatment of patients presenting with thromboembolic multivessel occlusions is the main topic of this chapter.