PMC8422417_01
Preoperative radiological examinations. (a) Initial axial-view diffusion-weighted magnetic resonance imaging (MRI) shows acute stroke within the territory of the lenticulostriate artery. (b and c) Initial axial-view computed tomography (CT) shows a high-density spot (b), and axial-view T1-weighted MRI shows a high-intensity spot at the base of the anterior perforated substance (c). (d and e) Initial multiplanar reconstruction MR angiography (slab: 15.0 mm thickness) (d) and CT angiography (e) on coronal view show an aneurysm separate from the proximal middle cerebral artery. (f) Digital subtraction angiography at the 2-week follow-up shows the aneurysm has grown.
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F1
Initial magnetic resonance imaging (MRI) and computed tomography (CT) of the head demonstrated acute infarction of the left basal ganglia, but no subarachnoid hemorrhage [Figure 1a and b]. A small, high-density spot on CT and high-intensity spot on T1-weighted MRI was shown beside the infarction [Figure 1b and c]. Subsequent MR angiography and CT angiography (CTA) demonstrated what appeared to be a 2.3-mm fusiform aneurysm with a left LSA origin [Figure 1d and e]. However, DSA revealed filling of 7.8 mm of the fusiform aneurysm near the left M1 segment, with the body of the aneurysm separate from M1 [Figure 1f].
Intraoperative microscope views. (a-f) A left frontotemporal approach shows the thrombosed aneurysm (asterisk) and perforators (triangle) of the left proximal middle cerebral artery (M1) (a), some small lenticulostriate artery (LSAs) and arteries supplying the surrounding brain (arrows) adherent to the surface of the aneurysm (b), collapsed M1 after neck clipping with fenestrated clip without thrombectomy (c), thrombectomy of the aneurysm with trapping of M1 (d), collapsed small LSA adherent to the aneurysm (arrow) (e), and preserved M1 and LSA (triangle) flow after thrombectomy-clip reconstruction with indocyanine green videoangiography (f). Fr, frontal lobe; Tm, temporal lobe.
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F2
The aneurysm was brown in color and was diagnosed as a thrombotic aneurysm [Figure 2a and b]. Simple neck clipping was unsuitable, because M1 was collapsed with thrombus after neck clipping, so partial thrombectomy was performed with temporary clips on the parent artery without heparin administration [Figure 2c and d]. After thrombectomy, neck clipping with a fenestrated clip was performed, preserving the parent artery and LSAs, but not preserving one of the small perforator's adherents to the aneurysm [Figure 2e and f].
Postoperative imaging. (a) Diffusion-weighted magnetic resonance imaging shows new infarction (arrow) beside the previous infarction (double arrow). (b and c) Digital subtraction angiography (DSA) and 3D-DSA (c) show no filling of the aneurysm and preservation of M1 and the perforators (triangle).
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F3
Postoperatively, right hemiparesis re-aggravated, and a small new infarction was detected on MRI in the basal ganglia beside the previous infarction [Figure 3a]. The aneurysm was not filled, and the left M1 and LSAs were well preserved on DSA [Figure 3b and c].