What are two examples of types of true aneurysms?

True aneurysms are defined as localized dilations of a blood vessel wall involving all three layers of the vessel: the intima, media, and adventitia. The most commonly recognized types of true aneurysms are fusiform and saccular.

Fusiform aneurysms are characterized by a symmetrical, spindle-like shape that uniformly enlarges around the entire circumference of the vessel segment. This type typically occurs along arteries and can involve a significant length of the vessel.

Saccular aneurysms, on the other hand, present as a localized outpouching or bulge on one side of the artery, resembling a sac. This form of aneurysm often results from pathological weakening of the vessel wall and is commonly observed at branching points of arteries.

This understanding of fusiform and saccular aneurysms differentiates them from other terms such as exaggerated or reduced, which do not apply to the anatomical structure of aneurysms, and acute or chronic, which describe time frames rather than specific morphological characteristics. Central and peripheral merely refer to anatomical locations and do not specify the type of aneurysm. Thus, the correct identification of fusiform and saccular as types of true aneurysms is key for recognizing and diagnosing these vascular