A fusiform intracranial aneurysm can be defined as a diffuse dilatation of an arterial segment such that a large percentage of the vessel’s circumference is pathologically dilated. These aneurysms are distinguished form saccular (aka: berry) intracranial aneurysms in that they do not harbor an aneurysm neck that aids with surgical exclusion of the lesion from the native circulation. Treatment of fusiform intracranial aneurysms is technically challenging because of the lesion’s broad involvement of the arterial lumen and the absence of a distinct aneurysm neck that can help during lesion obliteration. These lesions often present with critical branch vessels arising from the fusiform segment. Preservation of flow through the branch vessel can be difficult because elimination of the fusiform segment may lead to branch vessel occlusion and subsequent ischemic stroke in the branch vessel’s supplied brain territory.
This article describes a patient with an unruptured fusiform Vertebral Artery (VA) aneurysm where the Posterior Inferior Cerebellar Artery (PICA) arose from the diseased segment of the aneurysmal. Aneurysm treatment was achieved using multiple catheters, stents, and coils through a transcirculatory approach.