Which statement defines a false aneurysm?

A false aneurysm, also known as a pseudoaneurysm, occurs when there is a breach in the arterial wall that allows blood to leak out and accumulate in the surrounding tissue, creating a well-defined hematoma that communicates with the artery. This situation typically arises from a dissection or rupture in the arterial wall, where the layers of the artery become separated or damaged.

In this case, the dissection allows blood to flow outside of the normal confines of the artery while still being adjacent to it—this is the essence of a false aneurysm. As such, choosing a statement that highlights the role of dissection in the formation of a false aneurysm correctly identifies the underlying mechanism that distinguishes it from a true aneurysm, which involves the dilation of all three layers of the vessel wall.

The other statements pertain to different aspects of vascular pathology but do not accurately describe the characteristics of a false aneurysm. For example, while high blood pressure can contribute to vascular issues including true aneurysms, it is not a defining feature of false aneurysms. Likewise, a rupture in an artery may refer to any kind of rupture rather than specifically the formation of a false aneurysm, and a false aneurysm does not involve weakening of all