Berry aneurysms are what type of aneurysms, and 90% are found at which points?

Berry aneurysms are what type of aneurysms, and 90% are found at which points?

• A. Dissecting; venous branch points
• B. Saccular; arterial branch points
• C. Mycotic; capillary points
• D. Fusiform; arterial trunks

Answer: (B)

Berry aneurysms are saccular (berry-shaped) aneurysms of cerebral arteries. They form as small sacs at sites where an artery divides, most commonly within the circle of Willis. About 90% occur at arterial branch points in this region, such as the junctions where the anterior communicating artery meets the anterior cerebral arteries or at the bifurcations of the posterior communicating/internal carotid and the middle cerebral artery. This predilection reflects inherent weakness at vessel branch points and the high hemodynamic stress there. They are not dissecting, mycotic, or fusiform aneurysms.

Berry aneurysms are saccular (berry-shaped) aneurysms of cerebral arteries. They form as small sacs at sites where an artery divides, most commonly within the circle of Willis. About 90% occur at arterial branch points in this region, such as the junctions where the anterior communicating artery meets the anterior cerebral arteries or at the bifurcations of the posterior communicating/internal carotid and the middle cerebral artery. This predilection reflects inherent weakness at vessel branch points and the high hemodynamic stress there. They are not dissecting, mycotic, or fusiform aneurysms.