An aneurysm is a localized dilation, swelling, or bulging of a blood vessel that occurs due to a weakness in the blood vessel wall. As a result, the diameter of the blood vessel becomes larger than normal. This makes the vessel wall progressively weaker, and it can sometimes rupture or dissect even under normal blood pressure, leading to internal bleeding.
Types
An aneurysm can occur at various locations in the aorta or other arteries. The most common aortic aneurysms are found in the abdominal or chest cavity. We distinguish between a thoracic, abdominal, and thoracoabdominal aneurysm.
Thoracic Aortic Aneurysm
A thoracic aortic aneurysm (TAA) is a localized dilation of the aorta in the chest cavity (aorta thoracalis). A thoracic aortic aneurysm can occur at the level of the aortic root, ascending aorta, aortic arch, or descending aorta.
From left to right:
Aortic root aneurysm, ascending aorta aneurysm, aortic arch aneurysm, descending aorta aneurysm – © smart.servier.com
Abdominal Aortic Aneurysm
An abdominal aortic aneurysm (AAA) is a localized dilation of the aorta in the abdominal cavity (aorta abdominalis). This type of aneurysm is the most common. We distinguish between suprarenal, pararenal, subrenal, and infrarenal aortic aneurysms. This classification is based on the anatomical location relative to the renal arteries (arteriae renales).
Thoraco-abdominal Aortic Aneurysm
Sometimes, multiple adjacent sections of the aorta are involved in a single large aneurysm. In a thoraco-abdominal aortic aneurysm (TAAA), both the thoracic aorta (in the chest) and the abdominal aorta (in the abdominal cavity) are dilated.
