rĭzəm), localized dilatation of a blood vessel, particularly an artery artery, blood vessel that conveys blood away from the heart . Except for the pulmonary artery, which carries deoxygenated blood from the heart to the lungs, arteries carry oxygenated blood from the heart to the tissues...... Click the link for more information. , or the heart heart, muscular organ that pumps blood to all parts of the body. The rhythmic beating of the heart is a ceaseless activity, lasting from before birth to the end of life.
..... Click the link for more information. . Dilatation of an artery, and therefore weakness of that portion of the arterial wall, may be rarely congenital, or it may be caused by syphilis syphilis (sĭf`əlĭs), contagious sexually transmitted disease caused by the spirochete Treponema pallidum
..... Click the link for more information. , hypertension hypertension or high blood pressure, elevated blood pressure resulting from an increase in the amount of blood pumped by the heart or from increased resistance to the flow of blood through the small arterial blood vessels (arterioles).
..... Click the link for more information. (high blood pressure), arteriosclerosis arteriosclerosis (ärtĭr'ēōsklərō`sis)
..... Click the link for more information. , bacterial and fungal infections, or penetrating injury as from a bullet or knife. An aneurysm may be asymptomatic or it may cause varying symptoms, depending upon its location and size and on whether the expanding mass is pressing on adjacent nerves or vital organs. The weakened arterial walls of an aneurysm are always in danger of sudden rupture, with resulting hemorrhage and death.
Aneurysms occur most commonly in the large arteries; the aorta aorta (āôr`tə), primary artery of the circulatory system in mammals, delivering oxygenated blood to all other arteries except
..... Click the link for more information. , the largest vessel in the body, is the one most often affected. Ventricular aneurysms of the heart often occur after myocardial infarctions myocardial infarction or heart attack is usually caused by a blockage in one of the coronary arteries that supply blood to the heart muscle. The blockage typically occurs when a blood clot (see thrombosis ) lodges in an area already narrowed by arteriosclerosis ; other
..... Click the link for more information. . Aneurysms also occur in the arteries within the skull and in other areas of the body.
Aneurysms can be detected by echocardiogram, spin echo magnetic resonance imaging scans, coronary arteriograms, and biplane ventriculograms. Treatment, where feasible, may involve surgery to remove the aneurysm or the insertion of coiled wire to close it off. Coiled wire can only be used on aneurysms that are connected to the blood vessel by a narrowed neck. The coiling fills the aneurysm, obstructing the flow of blood into the dilatation, and blood clots form around the wire, preventing the aneurysm from bursting. Surgical excision of the dilated saclike portion of the affected artery sometimes requires the replacement of that portion by a synthetic graft, a section of vessel (made of polymer fiber) that is similar in size.
aneurysm
Blood-filled protrusion in the wall of a blood vessel (usually an artery, and particularly the aorta). Disease or injury weakens the wall so that normal blood pressure makes it balloon out. Typically, the two inner layers rupture and the outer layer bulges. In a false aneurysm, all three layers rupture and surrounding tissues hold the blood in place. Symptoms vary with size and location. Aneurysms tend to enlarge over time, and blood-vessel walls weaken with age. Many aneurysms eventually burst, causing serious, even massive, internal bleeding; aortic aneurysm rupture causes severe pain and immediate collapse. Rupture of an aneurysm in the brain is a major cause of strokes. Treatment can consist of simply tying off a small vessel; more serious aneurysms require surgery to replace the diseased section of artery with a plastic graft.
aneurysm, aneurism
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