J Cerebrovasc Endovasc Neurosurg.  2021 Sep;23(3):240-244. 10.7461/jcen.2021.E2020.10.004.

A case of an unruptured duplicated middle cerebral artery aneurysm–An unusual presentation of the distal internal carotid artery aneurysm

• Oh BK
• Kim YH
• Kim CH
• Lee SW
• Sung SK
• Song GS

• KMID: 2520883
• DOI: http://doi.org/10.7461/jcen.2021.E2020.10.004

Abstract

The duplicated middle cerebral artery (DMCA) is an anatomic variation that arises from the distal internal carotid artery (ICA) and supplies blood to the middle cerebral artery (MCA) territory. Aneurysms of the DMCA have been reported in 36 cases in 2020. We also report a case of a 3.7 mm saccular aneurysm originating from the DMCA. A 52-year-old woman visited our hospital with worsening headache. She had no neurological abnormalities. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) revealed a right distal ICA aneurysm at the anterior choroidal artery. Cerebral angiography was performed to confirm the shape and the size of the aneurysm. Cerebral angiography revealed that the vessel that was originally identified as the anterior choroidal artery by the MRA was actually the duplicated MCA that was originating from the aneurysm neck and was supplying the MCA territory. The patient’s aneurysm was clipped using a transsylvian approach and she recovered without any neurological symptoms. DMCAs are rare and often associated with aneurysms and require preoperative evaluation to confirm the vascular status, aneurysm characteristics, and the shape of the parent artery.

Keyword

Indocyanine green; Temporary arterial occlusion; Aneurysm; Intracranial; Cerebral blood flow

Figure

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  Fig. 1. Magnetic resonance angiography showing a right distal ICA aneurysm (arrow) with lateral projection, suggestive of a typical AChA aneurysm. ICA, internal carotid artery; AChA, anterior choroidal artery.

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  Fig. 2. Conventional cerebral angiogram of the right ICA (A) AP view of the right ICA angiogram demonstrating type B DMCA. Note the sharp separation angle from the ICA. (B) Oblique view of the right ICA angiogram showing the territories supplied by the DMCA (arrow heads). ICA, internal carotid artery; DMCA, duplicated middle cerebral artery.

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  Fig. 3. Intraoperative findings (A) Intraoperative microscopic view showing the DMCA (arrows) and related aneurysm. Note the DMCA running laterally to supply the anterior pole of the temporal lobe. (B) Microscopic view showing well clipped aneurysm. (C) ICGVA demonstrating the patent DMCA flow. DMCA, duplicated middle cerebral artery; ICG-VA, indocyanine green video angiography.

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  Fig. 4. Postoperative cerebral angiography revealing the complete occlusion of the aneurysm and the patent DMCA. DMCA, duplicated middle cerebral artery.

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