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The most common site for an arterial aneurysm is the abdominal aorta. A true aneurysm results from formation of a sac by the arterial wall with at least one unbroken layer. It is most often associated with atherosclerosis. A false aneurysm usually is caused by trauma. In this case, the wall of the blood vessel is ruptured and blood escapes into surrounding tissues and forms a clot. Because of pressure within the clot arising from the heart's contractions, the clot often pulsates against the examiner's hand as does a true aneurysm.
Although atherosclerosis is responsible for most arterial aneurysms, any injury to the middle or muscular layer of the arterial wall (tunica media) can predispose the vessel to stretching of the inner and outer layers of the artery and the formation of a sac. Other diseases that can lead to an aneurysm include syphilis, cystic medionecrosis, certain nonspecific inflammations, and congenital defects in the artery.
It is possible for a person to be unaware of a small aneurysm for years. About 80 per cent of all abdominal aneurysms are palpable and may be noticed on a routine physical examination. One should be particularly alert to the possibility of an aneurysm in persons with a history of cardiovascular disease, hypertension, or peripheral vascular disease.
Aneurysms tend to increase in size, presenting a problem of increasing pressure against adjacent tissues and organs and a danger of rupture. When an aneurysm ruptures, a critical situation ensues. The patient with a ruptured aortic aneurysm exhibits severe pain and blood loss, leading to shock. A ruptured cerebral aneurysm produces neurologic symptoms and can resemble the clinical picture of stroke syndrome.
Treatment of aneurysm depends on the vessel involved, size of the aneurysm, and general health status of the patient.
an·eu·rysm(an'yū-rizm), Avoid the misspelling aneurism.
aneurysmA lesion characterised by a weakness in the wall of an artery, vein, or cardiac ventricle, resulting in blood-filled dilation or ballooning, or splitting of the wall.
Pulsating mass, bruit (aneurysmal bruit over the swelling), ± symptoms from pressure on contiguous parts.
aneurysmSurgery A weakened or attentuated site on the wall of an artery, a vein or the ventricle, which has stretched or ballooned and filled with blood or, in an artery, resulting in a splitting of the wall, leading to pooling of blood in the vessel wall Clinical Pulsating mass, bruit–aneurysmal bruit over the swelling, ± symptoms from pressure on contiguous parts. See Abdominal aortic aneurysm, Aortic aneurysm, Berry aneurysm, Cerebral aneurysm, Mycotic aneurysm, Ruptured aortic aneurysm.
aneurysm, aneurism (an'yu-rizm) [Gr. aneurysma, a widening]
As people age, the combined effects of high blood pressure and atherosclerotic weakening of arteries produce most aneurysms in the aorta. Congenital malformations of arteries in the circle of Willis are relatively common causes of aneurysms in the brain. Aneurysms in the chest or peripheral arteries are sometimes caused by blunt trauma or by bacterial or mycotic infection.
abdominal aortic aneurysmAbbreviation: AAA
The patient is usually asymptomatic, and diagnosis is made accidentally during a routine physical examination or abdominal x-ray or during screening of the elderly hypertensive male. Serial ultrasounds confirm the diagnosis and determine the size, shape, and location of the aneurysm. Small, asymptomatic aneurysms may be followed over time, rather than repaired (see below). Computed tomography, magnetic resonance imaging, or aortography may assist in confirming the diagnosis and the condition of proximal and distal vessels.
Symptoms, when present, include generalized abdominal pain, low back pain unaffected by movement, and sensations of gastric or abdominal fullness. Sudden severe lumbar or abdominal pain radiating to the flank and groin, esp. if associated with tachycardia and hypotension, may indicate enlargement or imminent rupture. Signs can include a pulsating mass in the periumbilical area and a systolic bruit over the aorta.
Untreated abdominal aortic aneurysms gradually enlarge and in some instances rupture. The likelihood of rupture increases for aneurysms that are larger than 5.5 cm. Surgical repair is recommended for all aneurysms larger than 6 cm. If an aneurysm is tender and known to be enlarging rapidly (no matter what its size), surgery is strongly recommended. Surgical therapy consists of replacing the aneurysmal segment with a synthetic fabric (Dacron) graft. Immediate surgery is indicated for a ruptured aortic abdominal aneurysm. An alternative treatment to traditional laparotomy is to insert a bypass graft percutaneously into the aorta.
In acute dissection of an abdominal aortic aneurysm, oxygenation, blood pressure and cardiac rhythm are closely monitored, and a pulmonary artery line may be inserted to monitor hemodynamics. The patient is observed for signs of rupture, which may be fatal. He will require an intravenous line via a large-bore catheter, a urinary catheter, and an arterial line and pulmonary artery catheter to monitor fluid and hemodynamic balance. Additionally, cardiac monitor electrodes will be placed, and a nasogastric tube inserted.
Prescribed medications are administered to manage contributory factors such as hypertension and hypercholesterolemia; a beta-adrenergic blocking agent may be prescribed to reduce the risk of expansion and rupture. The patient is instructed in their use and taught about adverse effects that should be reported. In acute aortic rupture, admission to the intensive care unit is arranged, a blood sample is obtained for typing and cross-matching, and a large-bore (14G) venous catheter is inserted to facilitate blood replacement. The patient is prepared for and informed about elective surgery if indicated or emergency surgery if rupture occurs. The patient will require an intravenous line via a large-bore catheter, a urinary catheter, and an arterial line and pulmonary artery catheter to monitor fluid and hemodynamic balance. Additionally, cardiac monitor electrodes will be placed, and a nasogastric tube inserted. During surgery the patient will be intubated and mechanically ventilated, and such therapies will most likely still be in place postoperatively in the ICU.
Desired outcomes include the patient's ability to express anxiety, use support systems, and perform stress reduction techniques that assist with coping; demonstrated abatement of physical signs of anxiety; avoidance of activities that increase the risk of rupture; understanding of and cooperation with the prescribed treatment regimen; ability to identify indications of rupture and to institute emergency measures; maintenance of normal fluid and blood volume in acute situations; and recovery from elective or emergency surgery with no complications. Generally post-operative patients are assisted to ambulate by the second day after surgery. Pain management and psychological support are extremely important during the acute postoperative period.
Because of the relatively high incidence of AAA in men over age 60 (esp. smokers or men with intermittent claudication) and patients with myesthenia gravis, screening for AAA is recommended for these people.
Bérard's aneurysmSee: Bérard's aneurysm
Charcot-Bouchard aneurysmSee: Charcot-Bouchard aneurysm
racemose aneurysmCirsoid aneurysm.
aneurysmA berry-like or diffuse swelling on an artery, usually at or near a branch, and caused by localized damage or weakness to the vessel wall. Aneurysms can also involve the heart wall after a section has been weakened. See also BERRY ANEURYSM. The term derives from the Greek anaeurusma , a widening.
aneurysmdilation of an artery wall, a sac formed by abnormal dilation of the weakened wall of a blood vessel.
an·eu·rysm(an'yūr-izm) Avoid the misspelling aneurism.
Patient discussion about Aneurysm
Q. What are the causes of aneurysm?
Q. Can an aneurysm repair it self on her own? A friend of mine was diagnosed with an aneurysm. At first he was sure he is going to have a surgery, but afterwards his doctor told him he should get medical treatment. I don't understand - how come some people need a surgical repair while others just take medications? I know this is a serious condition that is life threatening can an aneurysm repair it self on her own? Or maybe when his doctor didn't recommend surgery he malpractices? the reason that I ask is that all the other people that I heard of that had an aneurysm had a surgery, and I don't really trust this doctor.
Anyway if you want you can go to your GP and ask him why didn't he offer you the surgical treatment.
Q. Could I be going through a Brain aneurysm? i woke up in the night with a bad headache in the back of my head and above my eye. never had a headache like that. but all day today have not had the headache. could this be an aneurysm?