PMC5791511_01
Cerebral angiography displaying a giant partially thrombosed right vertebral artery (VA, V4) dissecting the aneurysm from the PICA origin to the VA-basilar junction
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F1
A computerized tomography scan (angio-CT), and later cerebral angiography, displayed a giant partially thrombosed right VA (V4) dissecting aneurysm [Figure 1], distal to the posterior inferior cerebellar artery (PICA) origin, extended to the VA-basilar junction.
Magnetic resonance imaging (MRI) showing the partially thrombosed giant aneurysm with mass effect on the brainstem
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F2
Magnetic resonance imaging (MRI) of the posterior fossa confirmed the presence of a giant aneurysm [Figure 2], partially thrombosed, with mass effect on the brainstem.
VA angiograms demonstrating the placement of two diversion flow stents (arrows): the first in the left VA-basilar junction to exclude the right VA and the second in the right VA-PICA junction (a). An initial intra-aneurismal stasis of contrast is visible (b)
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F3
Before discharge, VA angiograms demonstrated correct placement of diversion flow stents [Figure 3] and an initial stasis of contrast [Figure 4].
Three months later the angiography shows good initial results for the endovascular procedure with dimensional reduction of the aneurysmal sac (a). The closure of the aneurysm patency from the left vertebral artery flow (b)
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F4
Before discharge, VA angiograms demonstrated correct placement of diversion flow stents [Figure 3] and an initial stasis of contrast [Figure 4].
Angiogram (a) and MRI (b) in the following 9 months shows an enlargement of the patency of the aneurysm and of the mass effect on the brainstem
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F5
Unfortunately, a subsequent magnetic resonance imaging (MRI) and angiogram [Figure 5] performed at 9 months after endovascular stenting showed persistent filling and continued growth of the aneurysm, which remained partially thrombosed and maintained a remarkable mass effect on the brainstem.
Angiography performed at 1 year after stenting. Balloon (blue arrow) test occlusion of the right vertebral artery and right PICA. Collateral arteries (red arrow) from the right SCA supplying the territory of the ipsilateral PICA and filling a small part of the aneurysm (green arrow)
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A right and left vertebral angiogram with an occlusion test [Figure 6] was performed using a temporary-occlusion silicone balloon catheter placed at the right VA just proximal to the stent in the VA-PICA.
The aneurysmal sac identified and isolated from the surrounding tissue and cranial nerves
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The aneurysmal sac was identified and isolated from the surrounding tissue and cranial nerves [Figure 7].
A temporary Yasargil clip positioned on the distal part of the PICA, partial aneurysmectomy and application of a fenestrated clip to maintain the PICA patency
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The decompression and a partial aneurysmectomy proceeded until it was possible to apply a fenestrated clip to maintain the PICA patency and exclude the distal aneurysmal VA dilatations [Figures 8 and 9].
The photograph shows the placement of the fenestrated clip and the progression of aneurysmectomy after the removal of the temporary clip
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The decompression and a partial aneurysmectomy proceeded until it was possible to apply a fenestrated clip to maintain the PICA patency and exclude the distal aneurysmal VA dilatations [Figures 8 and 9].
Postoperative angiogram (performed 4 months after surgery) showing a complete occlusion of the aneurysm and also the PICA (a, lateral view; b, anteroposterior view)
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The angiogram confirmed the right PICA occlusion and the exclusion of the aneurysm from the circulation [Figure 10].
The MRI shows a significant reduction of the mass effect (a and b)
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MRI highlighted significant reduction of mass effect [Figure 11].