Large basilar perforator pseudoaneurysm: A case report

Abstract

Basilar perforator aneurysms are rare and a communication between a basilar perforator and a separate pseudoaneurysm cavity is extremely rare. We describe a case presenting with high grade subarachnoid hemorrhage which on further investigation delineated a 2-3 mm dissecting basilar perforator aneurysm communicating superiorly into a contained 6 mm pseudoaneurysm cavity. This case illustrates an unusual neurovascular pathology with low potential for successful endovascular treatment such as coil embolization or intracranial flow diverter stenting. Conservative medical management remains the main stay of treatment for such poor surgical candidates.

Keywords: Basilar perforator aneurysm; CT angiography; acute subarachnoid hemorrhage; endovascular coil embolization; flow diversion stenting.

Figure 1.

(a, b) Initial axial non-contrast CT scans demonstrate Fisher grade 4 subarachnoid hemorrhage more pronounced at the prepontine cistern with intraventricular extension into both lateral ventricles resulting in supratentorial hydrocephalus. (c, d) Axial and coronal maximum intensity projection CTA reconstructions demonstrate a sidewall aneurysm arising from the basilar artery (small arrow) with adjacent contrast cavity suspicious for pseudoaneurysm (large arrow).

Figure 2.

(a–c) Left vertebral artery serial anteroposterior DSA images and (d) right vertebral artery 3D DSA reconstruction demonstrate a small aneurysm (solid arrow) arising from a left basilar artery perforator (asterisk) connected by a short stalk (arrowhead) to a larger pseudoaneurysm cavity (dotted arrow), opacified in the delayed capillary and venous phases.

Figure 3.

(a) Right vertebral anteroposterior and (b, c) bilateral oblique DSA images performed after 4 days from the initial angiogram demonstrate normal appearance of the basilar artery with no evidence of the sidewall basilar artery aneurysm or the pseudoaneurysm cavity suggesting spontaneous thrombosis, but also poor visualization and probable interval occlusion of the associated basilar perforator.