No hypothesis of saccular aneurysm formation and rupture has been uniformly accepted and the pathogenesis of aneurysms remains uncertain. The main controversy is whether they are congenital or acquired lesions and to what extent environmental factors influence development. The congenital argument suggests that there is a genetic pre-disposition to the development of medial wall or internal elastic lamina defects, supported by the high frequency of multiple aneurysms, familial tendency and their association with AVMs and inherited diseases. The degenerative theory describes an acquired defect in the arterial wall as a result of hemodynamic shear forces, supported by the increasing frequency of aneurysms seen with age, hypertension, smoking and atherosclerosis. They also commonly develop at bifurcations or on high-flow feeding vessels of AVMs, where vascular stresses are maximal.
Aneurysm formation is probably a multifac-torial process in which a genetic pre-disposition combines with secondary risk factors to create the lesion. Identification of those factors contributing to this process can focus future screening strategies and enhance screening yield.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...