Objective: Detection of acute arterial occlusion in an anomalous middle cerebral artery (MCA) is challenging in an emergency setting because of its rarity.
Case Presentation: We report an 81-year-old woman who presented with acute occlusion of a duplicated middle cerebral artery (DMCA). Although the absence of the superior trunk of the left MCA was identified on preoperative imaging, initial angiography showed no typical sign of the occluded vessel. Repeated angiography eventually revealed retrograde arterial flow parallel to the other visible MCA trunk, which raised the possibility of a DMCA. The occlusion occurred at the origin of the DMCA originating from the internal carotid artery terminus, which obscured its presence. Mechanical thrombectomy was performed and achieved complete recanalization. The DMCA had two trunks of approximately equal size. The patient completely recovered within 90 days.
Conclusion: Comprehensive knowledge of cerebrovascular anomalies is essential to identify the occluded branch faster and accurately and to avoid thrombectomy-related complications in endovascular recanalization therapy. Relevant DMCA anatomy and tips for identifying an occluded DMCA are discussed.