Late Embolism Following Recanalization of Occluded Extracranial Internal Carotid Artery Dissection

Objective: The clinical course of extracranial internal carotid artery dissection (eICAD) treated with medical therapy alone is usually benign, but late embolism may cause intracranial large artery occlusion (iLAO). We report a new procedure to treat iLAO caused by eICAD. Case Presentation: A 47-year-old man patient presented with two episodes of transient right hemiparesis and mild neck pain. An emergent MRI detected a left internal carotid artery (ICA) occlusion but no new infarction. Because it was strongly suspected that eICAD was the cause, medical therapy was started, and the patient’s neurological condition was frequently checked to ensure prompt response if a late embolism developed. One day after onset, a follow-up MRI revealed recanalization of the ICA occlusion and eICAD without a new infarction. Unfortunately, a late embolism of the left middle cerebral artery occurred 2 days after onset. We started intravenous tissue plasminogen activator administration immediately after a CT scan. We performed a mechanical thrombectomy (MT), resulting in thrombolysis in cerebral infarction (TICI) score of 3. Subsequently, we performed carotid artery stenting (CAS) for eICAD. Ten days after the stroke, the patient’s National Institutes of Health Stroke Scale (NIHSS) score was 2. Conclusion: When treating iLAO due to eICAD by MT and CAS, further vascular injury and intracranial embolism must be prevented. We used proximal and distal protection in combination, employing an aspiration catheter to withdraw the stent retriever and deliver a distal embolic protection device before CAS. As a result, the patient’s condition improved.