Aneurysm, abdominal



Aneurysm, abdominal




LIFE-THREATENING DISORDER



With abdominal aneurysm, an abnormal dilation in the arterial wall generally occurs in the aorta between the renal arteries and iliac branches. Such aneurysms are four times more common in men than in women and are most prevalent in whites ages 50 to 80. More than 50% of all people with untreated
abdominal aneurysms die within 2 years of diagnosis, primarily from rupture of the aneurysm; more than 85%, within 5 years.


Causes

About 95% of abdominal aortic aneurysms result from arteriosclerosis; the rest, from cystic medial necrosis, trauma, syphilis, and other infections. These aneurysms develop slowly.

First, a focal weakness in the muscular layer of the aorta (tunica media), due to degenerative changes, allows the inner layer (tunica intima) and outer layer (tunica adventitia) to stretch outward. Blood pressure within the aorta progressively weakens the vessel walls and enlarges the aneurysm.


Signs and symptoms

Although abdominal aneurysms usually don’t produce symptoms, most are evident (unless the patient is obese) as a pulsating mass in the periumbilical area, accompanied by a systolic bruit over the aorta. Some tenderness may be present on deep palpation. A large aneurysm may produce symptoms that mimic renal calculi, lumbar disk disease, and duodenal compression. Abdominal aneurysms rarely cause diminished peripheral pulses or claudication unless embolization occurs.



Pain, rupture, and hemorrhage

Lumbar pain that radiates to the flank and groin from pressure on lumbar nerves may signify enlargement and imminent rupture. If the aneurysm ruptures into the peritoneal cavity, it causes severe, persistent abdominal and back pain, mimicking renal or ureteral colic.

Signs and symptoms of hemorrhage—such as weakness, sweating, tachycardia, and hypotension—may be subtle because rupture into the retroperitoneal space produces a tamponade effect that prevents continued hemorrhage. Patients with such rupture may remain in stable condition for hours before shock and death occur, although 20% die immediately.

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Jun 16, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Aneurysm, abdominal

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