Figure legends
Figure 1a-d: Axial view of the initial computed tomography (a)
showing left dominant intraventricular hemorrhage and hydrocephalus with
a small amount of subarachnoid hemorrhage along both frontal sulci.
Diffuse brain swelling can also be seen. Left internal carotid artery
(ICA) digital subtraction angiography (DSA) (b) with an anterioposterior
view showing occlusion of the supraclinoid ICA and basal and
leptomeningeal collateral vessels representing Moyamoya disease. A
pseudoaneurysm about 4.5 mm in size can also be seen at the distal
branch of the left posterior choroidal artery (red arrow). Left
vertebral artery DSA (c) also shows a 4 mm sized pseudoaneurysm at the
left posterior choroidal artery (red arrow). (d) The frontal branch of
the superficial temporal artery was selected as the donor artery for the
first revascularization surgery (yellow arrow).
Figure 2a-f: T2 weighted brain magnetic resonance imaging (MRI)
after the first superficial temporal artery-middle cerebral artery
anastomosis bypass (a) showing perilesional edema with herniated brain
tissue via the craniectomy site at the left frontoparietal lobe. Basal
brain single photon emission computed tomography (SPECT), b) showing
luxury perfusion in the herniated and swollen left frontotemporal lobe.
Immediate post-bypass intraoperative findings (c-d) showing severe brain
edema and patent anastomosis. T2 weighted image from four months after
the second bypass surgery. Follow-up MRI (e) showing resolved edema and
herniated brain tissue at the left frontoparietal lobe. Five months
after the second bypass surgery, follow-up basal brain SPECT (f) reveals
recovered luxury perfusion at the left frontotemporal lobe.
Figure 3a-h: Cerebral angiogram (Figure a-d) after rebleeding
attack. Left internal carotid artery (a) and vertebral artery (b)
digital subtraction angiography (DSA) showing an increased size of the
pseudoaneurysm compared with preoperative DSA (Figure 1b-c) to about 13
mm at the longest diameter (red arrow). Left external carotid artery
angiogram (c-d) showing non-patent superficial temporal artery-middle
cerebral artery anastomosis (dotted white arrow) after the first bypass
surgery. Selective lateral posterior choroidal angiogram and stand-alone
coiling of the re-ruptured pseudoaneurysm (e-f) preserving the lateral
choroidal anastomosis branches were performed. Postoperative six-month
follow-up angiography (g-h) showing total obliteration of the
pseudoaneurysm, the disappearance of the medullary tributaries from the
left lateral posterior choroidal artery, and patent anastomosis (dotted
black arrow).