What type of aneurysm occurs due to a tear in the intima layer of the vessel wall?

A dissecting aneurysm occurs when there is a tear in the intima layer of the vessel wall, allowing blood to flow between the layers of the artery wall. This condition is often characterized by the creation of a false lumen formed by the separation of the tunica media from the intima. As the blood accumulates in this space, it can lead to a narrowing or obstruction of the true lumen, potentially compromising blood flow.

The risk factors for this type of aneurysm include hypertension, connective tissue disorders, and a history of trauma. The occurrence of a tear elevates the risk of complications such as rupture or significant internal bleeding, making timely diagnosis and management critical.

Understanding this definition clarifies why a dissecting aneurysm, specifically linked to a tear in the intima layer, is the correct answer. Other types of aneurysms do not share this mechanism or definition, which solidifies the distinction between them and further elaborates on the characteristics of dissecting aneurysms.