PMC4722526_01
Primary computed tomography revealing subarachnoid hemorrhage and intracerebral hematoma predominantly in the anterior interhemispheric fissure (a). Initial digital subtraction angiography demonstrating a fusiform aneurysm of the left pericallosal artery (b). Follow-up digital subtraction angiography performed 20 days after the bleeding revealing enlargement of the aneurysm (c). Three-dimensional digital subtraction angiography indicating the paracentral artery originating from the aneurysmal sac (triple arrows) (d). Postoperative digital subtraction angiography showing disappearance of the aneurysm and patency of the interposition graft bypass. An arrow indicates the graft bypass. Left and right arrowheads indicate the anastomosis sites of the callosomarginal artery-superficial temporal artery-pericallosal artery bypass. Middle arrowhead indicates the anastomosis site of the superficial temporal artery-paracentral artery (e). Postoperative diffusion-weighted imaging showing no ischemic complications (f)
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F1
A computed tomography scan revealed subarachnoid hemorrhage (SAH) with intracerebral hematoma, predominantly in the anterior interhemispheric fissure, and intraventricular hematoma [Figure 1a]. Initial digital subtraction angiography (DSA) demonstrated a fusiform aneurysm with an irregular shape on the left pericallosal artery, 4.5 mm in maximum diameter [Figure 1b]. However, follow-up DSA performed 20 days after the onset revealed the enlargement of the aneurysm to 14 mm in maximum diameter and vasospasm of the left pericallosal artery [Figure 1c]. The left paracentral artery originated from the dome of this aneurysm, which would perfuse a motor area of the right lower limb [Figure 1d]. Postoperative magnetic resonance imaging showed no ischemic or hemorrhagic complications, and postoperative DSA revealed the patency of the interposition graft [Figure 1e and f].
An intraoperative photograph showing the anastomosed superficial temporal artery graft (a). Illustration showing an interposition graft bypass using the superficial temporal artery (b)
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F2
A frontal branch of the left STA, 8 cm in length, was harvested, and this STA was used as an interposition graft to reconstruct the left ACA in an end-to-side manner: Left callosomarginal artery (proximal side) - STA graft - left pericallosal artery (distal side) [Figure 2a and b]. Then, the origin of the left paracentral artery was cut and anastomosed to the STA graft in an end-to-side manner [Figure 2b].
H- and E-stained section of the resected aneurysm revealing features of a ruptured infectious pseudo-aneurysm (a). The arrows show vascular intima partially absent in an Elastica-Masson stained section (b). The adventitia of the resected anterior cerebral artery was invaded by many inflammatory cells in an H- and E-stained section (c)
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F3
Hematoxylin-eosin stained sections and Elastica-Masson stained sections of the resected aneurysm corresponded to the features of an infectious cerebral aneurysm [Figure 3a]. The vascular intima was globally hypertrophic and partially disappeared [Figure 3b]. No bacteria were detected in these sections, but the adventitia was invaded by many inflammatory cells [Figure 3c].