Silent delayed middle cerebral artery occlusion post-mechanical thrombectomy: A case report

Mechanical thrombectomy (MT) for atherothrombotic lesions entails significant risks, including reocclusion and the possibility of worsening stenotic changes through endothelial injury. We treated a 45-year-old male admitted to our hospital with the sudden onset of left hemiparesis. Magnetic resonance imaging (MRI) revealed an occlusion of the right middle cerebral artery (MCA). Immediate intravenous tissue plasminogen activator infusion followed by MT successfully reperfused the MCA, although residual stenosis persisted in the distal portion of the M1 segment. Following the procedure, the patient’s symptoms resolved, and he was discharged. Three months later, follow-up MRI showed reocclusion of the right MCA and hemodynamic changes indicating reduced cerebral blood flow and cerebrovascular reactivity in the MCA territory. Subsequently, extracranial–intracranial bypass surgery was performed, and the patient did not develop any new symptoms postoperatively. While the patient in this case did not develop permanent symptoms, diligent observation is imperative following MT due to the potential for delayed progressive stenosis or occlusion.