PMC3347490_01
Volume rendered 3-dimensional computerized tomographic angiography (3D CTA) images show bilateral A1 fenestrations (a) (arrows) and saccular aneurysm involving proximal end of the right A1 fenestration (b) (arrowhead). Postoperative digital subtraction angiography shows complete obliteration of the aneurysm involving proximal end of the right A1 fenestration (c) (arrowhead). 3D views of the left carotid circulation obtained from rotational angiogram show the left-sided fenestration (d) (arrow)
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F1
Computed tomography (CT) angiography performed at our institution revealed a small aneurysm at the proximal end of fenestrated right A1 segment and bilateral fenestrations of the A1 segments [Figure 1a and b]. Post-clipping angiography demonstrated complete obliteration of the aneurysm [Figure 1c and d].
PMC3347490_02
Postmortem specimen showing bilateral A1 fenestrations. Note that one large perforator originates from the large arm of the left fenestration on the left side and two from the large arm of the fenestration on the right side. Also, note very prominent right recurrent artery of Heubner on the right and again very prominent anterior communicating artery perforator. Inlet picture on left bottom corner shows magnified view of two of the perforating branches (arrowheads) originating from the small arm of the left A1 fenestration after the specimen is stained with luxol fast blue to overcome the transparency
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F2
The anomalous cerebral vessels (A1 segments, anterior communicating artery, and A2 segments) were isolated for further microscopic examination by cutting A1s proximally and A2s distally [Figure 2].