PMC6000718_01
A computed tomographic scan showing an enhanced mass in the anterior perforated substance (a) associated with a huge hematoma in the basal ganglia and temporal lobe. Post operative CT showed the hematoma was completely removal (b). Angiograms revealed a nidus fed by the anterior choroidal arteries (AChAs) and the lateral lenticulostriate arteries (LSAs) (c) and drained by the basal vein of Rosenthal (BVR), the deep middle cerebral vein (DMCV), and the anterior communicating vein in the delayed arterial phase (d)
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F1
APS [Figure 1a]. An endoscopic hematoma evacuation was promptly performed [Figure 1b]. The maximum diameter of the nidus was 25 mm with an SM grade of 3 [Figure 1c and d].
The MEP records showing the change before and after clamping an AChA (a and b) and an LSA (c and d). The amplitude decreased 1 minute after occlusion of one of the four AChAs (b). The amplitude decreased 5 minutes after occlusion of the most lateral LSA (d). They recovered soon after the declamp and did not change at the time of the dural closure (e)
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F2
There were four AChAs feeding the nidus, and the distal two were cut because the test occlusion for 5 min did not induce a depression of the motor evoked potential (MEP) [Figure 2a]. AChAs were preserved because the amplitude decreased 1 min after clamping [Figure 2b]. A few A1 perforators were also cut after the test occlusion. Tokyo, Japan) and the MEP was measured at 1 and 5 min after the occlusion. The LSAs were cut when the amplitude was not decreased [Figure 2c]. An LSA branching from the most distal part of the M1 segment was preserved because the amplitude decreased 5 min after clamping [Figure 2d], even though there was no MEP depression at 1 min. The MEP was maintained at the time of dural closure [Figure 2e].
Intraoperative photos. One of the LSAs was found to enter the nidus (arrow) but proved to be a passing artery (a). The nidus was demarcated, and the BVR remained (b). The intraoperative indocyanine green (ICG) videoangiography showed that the LSA remained and reflux of ICG was found in the BVR (c)
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F3
The preserved LSA was revealed passing through the nidus [Figure 3a]. The nidus was lifted from the APS after all the arteries supplying the nidus were cut [Figure 3b]. We confirmed that the nidus was not stained by indocyanine green (ICG), and that there was a reflux of the ICG in the BVR [Figure 3c].
Pre (a) and postoperative (b) angiograms showing the nidus completely obliterated, and two AChAs and a lateral LSA were successfully preserved (arrows)
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F4
Pre [Figure 4a] and postoperative [Figure 4b] angiograms showing the AVM had completely disappeared, and two AChAs and one LSA were preserved.