Nontraumatic, posterior circulation pseudoaneurysm of the basilar artery summit with complete spontaneous resolution: Case report and literature review

Abstract

Background:Intracranial pseudoaneurysms are rare vascular defects of arterial walls that are classically the result of traumatic injury, iatrogenic causes, or infection. Idiopathic pseudoaneurysms are seen even less frequently and are often related to atherosclerosis. Pseudoaneurysms are most commonly found along the distal wall of the internal carotid artery, however, can occur at any location in the cerebrovascular circulation. Treatment of these arterial defects is often challenging due to their frail nature.Case Description:A 61-year-old male with a history of hypertension presented with a severe, atypical headache without history of trauma. Computed tomography (CT) and computed tomography angiography (CTA) demonstrated diffuse subarachnoid hemorrhage. Imaging demonstrated a 3.5 mm pseudoaneurysm projecting distally from the basilar artery at the apex. Repeated imaging (CTA, digital subtraction angiography) demonstrated decreased size and flow associated within the aneurysm over the following 2 weeks; as such, the patient was managed conservatively. The patient was discharged in neurologically intact condition when imaging at 14 days confirmed complete and spontaneous resolution of the pseudoaneurysm.Conclusion:Idiopathic pseudoaneurysms that are commonly associated with atherosclerosis are most commonly managed surgically or endovascularly. Conservative approach may be considered in a select group of patients that exhibit decreased size and/or flow within the aneurysm in repeated imaging; spontaneous resolution was seen in the present case.

Intracranial Pseudoaneurysms: Evaluation and Management

“…The mechanism of spontaneous occlusion remains unclear. It may be due to vascular remodeling response to injury as well as spontaneous thrombus formation (84). Those studies suggest that some specific pseudoaneurysms may at least have a potentially benign course with conservative treatment.…”

“…Those studies suggest that some specific pseudoaneurysms may at least have a potentially benign course with conservative treatment. Observation might be considered in pseudoaneurysms with decreased size and flow in repeated conventional angiography compared with the initial images (84). However, a recent study reported an unusual course of a cerebral pseudoaneurysm (69).…”

“…Complete spontaneous resolution of pseudoaneurysms is considered to be an uncommon occurrence. Previous studies have demonstrated existence of spontaneous resolution in peripheral vessels or intracranial vessels, including the middle meningeal artery ( 80 , 81 ), basilar artery ( 82 – 84 ), posterior cerebral artery ( 85 ) and pericallosal artery ( 39 ). The mechanism of spontaneous occlusion remains unclear.…”

Fenestration deformity of the basilar artery trunk with an aneurysm

“…[5] Pseudoaneurysms do not have a normal vascular wall structure and are prone to rebleeding, endangering the patient's life. [5,6] However, there are no similar reports in PubMed. Endovascular therapy is currently the best treatment for basilar artery fenestration with an aneurysm.…”

“…[3,4] This study reports the case of a patient with basilar artery fenestration deformity and an aneurysm at the mid-distal junction. While pseudoaneurysm formation could not be excluded, [5,6] it is very rare in the clinic. Currently, little is known about this condition, and relatively few data based on experience with interventional therapies are available.…”