Aneurysms: Just waiting to erupt

MARTIAL-ARTS movie star Bruce Lee is thought to have died from it. The world was caught by surprised when Hollywood actor John Ritter also succumbed to the fatal disease.

Both celebrities perished from aneurysm. “A bulge in the wall of an artery, usually the aorta” is how the second home edition of The Merck Manual of Medical Information defines it. The aorta, which is about 1 inch in diameter, is the main artery that carries oxygen-rich blood from the heart through its branches to the entire body.

Experts have likened aneurysms to time bombs for good reason: You can be without symptoms until the faulty blood vessel bursts. “The bulge usually occurs in a weak area of the artery’s wall,” the Merck Manual explains. “The pressure of blood inside the artery forces the weak area to balloon outward.”

Aneurysms can develop anywhere along the aorta. Three-fourths of aortic aneurysms develop in the part that passes through the abdomen (abdominal aortic aneurysm), and the rest develop in the part that passes through the chest) thoracic aortic aneurysm). Aneurysms can also develop in the arteries at the back of the knee, the main arteries of the thighs, the arteries supplying the head, the arteries supplying the brain (cerebral aneurysm) and the arteries supplying the heart muscle. 

Are aneurysms dangerous? “Yes,” wrote Dr. Philip Chua in one of his features, “if it grows large enough [twice or larger than its normal diameter], increasing the risk of rupture.”

The other common danger of an aneurysm is blood clot. “A blood clot often develops in the aneurysm because blood flow inside the aneurysm is sluggish,” explains the Merck manual. “The clot may extend along the entire wall of the aneurysm. A blood clot may break loose, travel through the bloodstream and block arteries.”

Most likely to suffer

It is not known why aneurysms occur in some people and not others. “People with high blood pressure, high cholesterol and smokers are the most likely to suffer,” says Dr. Alfred Cheng, head of the cardiac clinic at the Mount Elizabeth Medical Center in Singapore. “Those with close relatives who have had aneurysms, and diabetics, are also at risk.”

Men are eight times more likely to have an aneurysm than women. In older people, almost all aneurysms are associated with arteriosclerosis. “This is commonly known as hardening of the artery due to constant and long-standing cholesterol build up in the inner wall of the artery,” Chua says. “Whenever we eat fatty foods like pork, beef, eggs, and dairy products, among others, the cholesterol level in our blood goes up, making our blood thicker and prone to blood-clot formation. As it circulates all over our body, this thick blood is painted on the inner wall of the arteries and adheres to the wall and, as weeks and months go by, this thick blood becomes clots, which ultimately mature into hardened plaques that are calcified and hard as bone. These plaques grow larger and ultimately fill up and obstruct the caliber of the artery, much like the junk blocking our sewer pipes in the kitchen sink over a period of time.”

Aside from arteriosclerosis, other causes of aneurysms include injuries, inflammatory diseases of aorta, hereditary connective-tissue disorders and some infectious diseases, such as syphilis.

No symptoms

As stated earlier, most aneurysms show no symptoms. But some people who have an abdominal aortic aneurysm often become aware of a pulsing sensation in their abdomen. As aneurysm grows, pain in the back or abdominal region, sometimes with bloating or nausea and vomiting, is felt. “If the aneurysm ruptures, a person will show signs of shock to due excessive bleeding—dizziness or fainting with weakness, sweating, rapid heartbeat and loss of consciousness,” the Pacific Vascular Research Foundation in the United States points out.

On the other hand, typical symptoms of thoracic aortic aneurysm are pain (usually high in the back), coughing, and wheezing. Rarely, a person coughs up blood because of pressure on or erosion of the windpipe or nearby airways. “Swallowing may be difficult if an aneurysm puts pressure on the esophagus, which carries food to the stomach,” informs the Merck manual.

Meanwhile, rupture of cerebral aneurysm may cause bleeding into the brain tissue, resulting in a stroke. “A ruptured cerebral artery aneurysm could definitely result in stroke when it breaks open, but the more common cause is the lack of blood in the brain due to blockage in the neck artery that normally supplies blood to the brain, or due to a blood clot,” Chua explains.

Diagnosis

The Pacific Vascular Research Foundation says aortic aneurysms can be diagnosed prior to rupture. Regular physical examinations can be helpful. One reason a doctor examines a patient’s abdomen during a routine exam is to feel for an abnormally pulsating aorta in the mid-abdominal region. Other tests include ultrasound examination and various radiological imaging studies including computerized tomography (CT), magnetic resonance imaging (MRI), and aortography (an x-ray procedure performed after injection of a dye that outlines the aneurysm).

Doctors may diagnose a thoracic aortic aneurysm based on symptoms, or they may discover the aneurysm by chance during a routine physical examination. Cerebral aneurysms can be detected by imaging tests, such as MRI, CT scans and angiograms (x-rays are used to produce pictures of the inside of blood vessels).

Treatment

Aneurysms that are less than 2 inches wide rarely rupture. In the case of abdominal aortic aneurysm, “the only treatment required may be antihypertensive drugs to lower blood pressure,” the Merck Manual states. “Aneurysms that are wider rupture fairly common, so doctors usually recommend surgery, unless surgery is too risky for a particular patient.” The risk of death during an operation for a ruptured aneurysm is about 50 percent. 

Because cerebral aneurysms are near the brain and are usually small, their diagnosis and treatment differ from those of other aneurysms. “Once detected, most brain aneurysms can be repaired with microsurgery,” the Boston-based Brain Aneurysm Foundation Inc. in the US says. “This type of surgery is performed with the aid of an operating microscope and tiny instruments. During surgery, the aneurysm is identified and removed. After the aneurysm is removed, the wound is closed.”

Chua advises that, if you suspect you might have aneurysm, the most prudent thing to do is to seek medical consultation. “An aneurysm could be serious, even fatal, when it leaks or ruptures.” 

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