Fusiform cerebral aneurysms typically develop in which artery?

Fusiform cerebral aneurysms typically develop in which artery?

• A. Basilar artery
• B. Circle of Willis
• C. Internal carotid artery
• D. Anterior communicating artery

Answer: (A)

Fusiform aneurysms involve a circumferential dilation along a segment of a vessel rather than a single outpouching with a neck. They tend to occur in the posterior circulation, where long segments of vessels are prone to degenerative changes and atherosclerosis from sustained high-flow stress. The basilar artery, as a central part of the vertebrobasilar system, is a classic site for this pattern of dilation. That’s why fusiform cerebral aneurysms are typically described as developing in the basilar artery. In contrast, aneurysms at branching points within the Circle of Willis, such as the anterior communicating or internal carotid artery segments, are more characteristically saccular (berry) aneurysms with a discrete neck. These distinctions help explain why the basilar artery is the best answer for fusiform aneurysms.

Fusiform aneurysms involve a circumferential dilation along a segment of a vessel rather than a single outpouching with a neck. They tend to occur in the posterior circulation, where long segments of vessels are prone to degenerative changes and atherosclerosis from sustained high-flow stress. The basilar artery, as a central part of the vertebrobasilar system, is a classic site for this pattern of dilation. That’s why fusiform cerebral aneurysms are typically described as developing in the basilar artery.

In contrast, aneurysms at branching points within the Circle of Willis, such as the anterior communicating or internal carotid artery segments, are more characteristically saccular (berry) aneurysms with a discrete neck. These distinctions help explain why the basilar artery is the best answer for fusiform aneurysms.