PMC4533420_01
Computed tomography reveals subarachnoid hemorrhage with thick subarachnoid clot in the cerebellomedullary cistern. Back streaming of the hemorrhage in the lateral ventricle is also seen.
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Computed tomography (CT) revealed SAH with thick subarachnoid clot in the cerebellomedullary cistern (Fig. 1).
Computed tomography angiography (CTA) revealing a pearl-and-string sign in the V4 portion of the right vertebral artery (left). Slices a, b, and c correspond to the pathological specimens (right). Photomicrograph showing serial axial slices of an entry-only dissecting aneurysm. Elastica van Gieson stain, original magnification x40. Panel a shows a slice taken from the narrowed lesion seen on CTA. The media is disrupted, and hematoma is seen just below the adventitia. The intravascular space is narrowed in this slice. Panel b shows a slice taken from the dilated lesion seen on CTA. The internal elastic lamina is disrupted, and the wall adjacent to the rupture site is only composed of fibrin and thin collagen, which forms a pseudoaneurysm. Panel c is a slice taken from the normal-appearing site seen on CTA. The internal elastic lamina is also disrupted in this specimen, while the intravascular space is relatively normal; this means that the angiographically "normal" lesion also includes the entry point.
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CTA revealed a pearl-and-string sign in the V4 portion of the right vertebral artery (Fig. 2, left ) and absence of a posterior inferior cerebellar artery (PICA) arising from the left side of the vertebral artery. The entry was contained within the normal segment of the proximal vertebral artery seen on preoperative CTA (Fig. 2, right ).
Operating view of the right-sided lateral suboccipital transcondylar approach. Panels A and B show the distal end of the dissecting aneurysm. A: Perforating branches of vertebral artery are seen just distal to the dissecting aneurysm. B: Vertebral artery trapping was performed while securing this perforating branch. C: The proximal end of the dissecting aneurysm. Trapping was performed and involved the entire length of dissecting aneurysm.
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Intraoperatively, no PICA was identified, but there was a penetrating branch arising just distal to the dissection (Fig. 3A). A distal clip was placed on the vertebral artery just proximal to the penetrating branch (Fig. 3B). The proximal end of the dissection was also obliterated by clipping while preserving perforators arising from intact segment of vertebral artery (Fig. 3C).
PMC4533420_02
Computed tomography reveals a Fisher Group three subarachnoid hemorrhage. The hematoma of the right side is dominant.
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CT showed SAH (Fisher group three) (Fig. 4). CTA revealed only an elevated margin proximal to the origin of the posterior communicating artery (PCoA) (Fig. 5).
Preoperative computed tomography angiography reveals only an elevated margin (arrow) proximal to the origin of the posterior communicating artery (arrow head).
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CT showed SAH (Fisher group three) (Fig. 4). CTA revealed only an elevated margin proximal to the origin of the posterior communicating artery (PCoA) (Fig. 5).
Operative view of the right anterior temporal approach. Dissecting aneurysm of the internal carotid artery is found in C2 to C1. The rupture point is found in the C2 portion (left, arrow head). The dissecting aneurysm extends to the distal portion of the C1 (right, arrow).
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ICA, and common carotid artery in the right neck. Intraoperatively, the rupture point was identified in the C2 portion (Fig. 6, left ), and the dissecting aneurysm extended to the distal portion of C1 (Fig. 6, right ).
Photomicrograph showing the disrupted internal elastic lamina and hematoma below the adventitia. The intravascular space is maintained within the normal range. Elastica van Gieson stain, original magnification x40.
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The true lumen was maintained with normal shape and size and without narrowing (Fig. 7).
Postoperative digital subtraction angiography showing external carotid-radial artery-M2 bypass with good retrograde flow and trapped C2 to C1 portion of the internal carotid artery.
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Postoperative DSA showed good patency of the EC-RA-M2 bypass with good retrograde flow to the proximal portion of the middle cerebral artery and ICA and disappearance of the dissecting aneurysm of the C1-C2 segment of the ICA (Fig. 8).
PMC4533420_03
Computed tomography revealing subarachnoid hemorrhage with thin clot around the prepontine and cerebellomedullary cistern.
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CT revealed SAH with thin clot around the prepontine and cerebellomedullary cistern (Fig. 9). CTA and DSA showed a pearl sign in the segment of V4, just distal to the bifurcation of the PICA.
Computed tomography angiography and digital subtraction angiography show a pearl sign in the segment of V4 just distal to the takeoff of the posterior inferior cerebellar artery (PICA). The PICA is not involved in the dissecting length on preoperative imaging.
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Of note, the PICA was thought not to be involved in the dissecting aneurysm on preoperative imaging (Fig. 10).
Left-sided lateral suboccipital transcondylar approach was performed. The orifice of the posterior inferior cerebellar artery (arrow) is contained within the dissecting aneurysm (arrow head).
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Intraoperatively, the orifice of PICA was involved by the dissecting aneurysm (Fig. 11).
Photomicrograph showing a ruptured portion of an entry-only dissecting aneurysm in a dilated lesion. The internal elastic lamina is disrupted, resulting in pseudoaneurysm. Elastica van Gieson stain, original magnification x40 (left), x400 (right).
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The entry was in the angiographically dilated lesion (Fig. 12).