An aneurysm can be defined as a blood filled dilation (expansion or bulge) of a blood vessel caused either by a disease or the weakening of the vessel wall. The aorta is the body’s largest artery that stems off the left ventricle, which is the lower left quadrant of the heart. This artery is responsible for carrying and delivering oxygenated blood from the heart to other leading arteries in the body.
The term aneurysm is used when the artery is said to be 50% or more dilated. A dilated vessel is simple a vessel that has increased in diameter. The artery has to be dilated more than 3.5 centimetres to be termed an aneurysm.? Ectasia is a term used to define the dilation or distension of a structure and is also the term that is used when this condition is moderately severe.? An aged vessel has less elastic fibres and smooth muscle to protect the vessel and hence, the condition is a common finding in an aging population.
Aortic aneurysms can occur anywhere along the aortic artery however are most commonly known to occur in the abdominal region bellow the kidneys but have also been known to present in the chest and are termed abdominal aneurysm and thoracic aneurysm respectively. It is a serious disturbance of the blood vessel and poses a great risk when the aneurysm ruptures leading to an abdominal haemorrhage. A haemorrhage is the clinical term for the loss of blood (bleeding) from the body’s circulatory system.
There are two broad classifications of aneurysms a true aneurysm and a false aneurysm. A true aneurysm is characterized by damage that is done to all three layers of the aorta, which results in a substantially large swelling of the wall of the vessel. There are two sub divisions of a true aneurysm called a fusiform aneurysm and a saccular aneurysm. The fusiform, which is the more common of the two, is represented by a dilated symmetrical bulge of the entire section of the vessel where as the saccular corresponds to the outward swelling of only a portion or segment of the artery. A false aneurysm which is medically termed a pseudoaneurysm is a tear in the lining of the vessel where blood is then pooled on the outer layer of the artery mimicking that of a saccular aneurysm. This type of aneurysm is often caused during a surgical procedure that punctures the vessel or can be due to disease that damages the artery.