Aneurysm
An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall.[1] Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus (starting point) for clot formation (thrombosis) and embolization. As an aneurysm increases in size, the risk of rupture, which leads to uncontrolled bleeding, increases.[2] Although they may occur in any blood vessel, particularly lethal examples include aneurysms of the circle of Willis in the brain, aortic aneurysms affecting the thoracic aorta, and abdominal aortic aneurysms. Aneurysms can arise in the heart itself following a heart attack, including both ventricular and atrial septal aneurysms. There are congenital atrial septal aneurysms, a rare heart defect.
For other uses, see Aneurysm (disambiguation).Aneurysm
Aneurism
Risk factors for an aneurysm include diabetes, obesity, hypertension, tobacco use, alcoholism, high cholesterol, copper deficiency, increasing age, and tertiary syphilis infection.[19]: 602 Connective tissue disorders such as Loeys-Dietz syndrome, Marfan syndrome, and certain forms of Ehlers-Danlos syndrome are also associated with aneurysms. Aneurysms, dissections, and ruptures in individuals under 40 years of age are a major diagnostic criteria of the vascular form of Ehlers-Danlos syndrome (vEDS).[21]
Specific infective causes associated with aneurysm include:
A minority of aneurysms are associated with genetic factors. Examples include: