Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, May 3, 1994 TAG: 9405050001
SECTION: EXTRA PAGE: 1 EDITION: METRO
SOURCE: Jane Brody
DATELINE: LENGTH: Long
Hundreds of thousands of unsuspecting people are walking around with what amounts to a time bomb in their aortas: a weakened portion, or aneurysm, that may rupture and kill them.
Studies by doctors at the Mayo Clinic in Rochester, Minn., revealed that aortic aneurysms in the abdomen have become three times more common in the last 40 years.
Each year some 15,000 Americans die of a ruptured aneurysm in the abdominal portion of the aorta. Yet few of those at high risk for developing this problem have undergone the simple, noninvasive tests that can detect it and lead to the crucial monitoring and treatment that could prevent a fatal rupture. Experts estimate that in 95 percent of patients, proper well-timed treatment can eliminate the fatal risk.
The aorta is like a tree trunk. Other major arteries branch off it, including the coronary arteries to the heart, the carotid and vertebral arteries to the head and the renal arteries to the kidneys.
There are branches to the arms, chest, abdomen, bowel, liver, pancreas, spleen and legs. Ultimately, the aorta nourishes every tissue, from the brain to the toes, with a constant supply of oxygen and nutrients.
So it should not be surprising that when the aorta has a problem, the whole body - indeed, the person's life - is threatened as well. By far the most serious problem that can affect the aorta is an aneurysm.
Aneurysms are swellings in the walls of arteries. The muscles in the arterial wall weaken, resulting in a bulge, and as the blood courses through the damaged area, the bulge may slowly enlarge.
Like a balloon that is overly inflated or a garden hose that has a weakened section or an automobile tire with a bubble in the side wall, aneurysms sometimes enlarge to the point where they burst.
When an aneurysm in a cerebral artery ruptures, the result is a hemorrhagic stroke. When there is a rupture in the aorta, massive amounts of blood can spill into the body cavity, causing a precipitous drop in blood pressure and, all too often, rapid death.
A ruptured aneurysm in the abdominal aorta is what killed Albert Einstein 39 years ago, and even today it is the 13th leading cause of death in this country.
More than half those who suffer such a rupture die before reaching the hospital and only half of those who make it to emergency surgery recover. Precious minutes are often lost while emergency room doctors try to unscramble the confusing symptoms of a ruptured abdominal aorta, which can mimic those of less serious problems like kidney stones.
Aneurysms can also occur in the chest, or thoracic, portion of the aorta, although these are less common than abdominal aneurysms.
In addition to the typical bulging aneurysm, there is what doctors call a dissecting aneurysm, in which blood gets between the inner and outer layers of the aorta, causing swelling of the outer wall and a narrowing of the passageway through the artery, which can diminish the blood supply to various organs. Dissecting aneurysms, too, can sometimes rupture.
Aneurysms are most likely to develop in people who are overweight, have high blood pressure (particularly if it is not well controlled), smoke cigarettes, are over 55 years old or have a family history of aortic aneurysm.
Patients with atherosclerosis (fatty deposits that clog the arteries) and those with a congenital disorder called Marfan syndrome are at increased risk of developing an aortic aneurysm. In rare cases, individuals are born with an inherent weakness in the wall of the aorta.
Aneurysms in the abdominal area enlarge slowly over a period of years. In theory, this means they can be discovered before they cause problems.
Unfortunately, aneurysms frequently produce no symptoms that would prompt a person to seek medical attention. But they can be picked up at a regular physical examination.
For example, an abdominal aneurysm often feels like a tender, throbbing lump under the skin and the patient or an examining doctor may discover the pulsating mass. Even if the lump cannot be felt, the doctor can often hear suspicious sounds of turbulent blood flow through a stethoscope on the abdomen.
When an abdominal aneurysm begins to leak, it may cause pain that radiates to the back and the groin. A thoracic aneurysm may cause pain if it happens to press on one of the bronchial tubes, lungs or other structures in the chest cavity.
If it presses on the esophagus, it can cause difficulty in swallowing. A dissecting aortic aneurysm in the chest area can cause chest pain that mimics a heart attack and a ``tearing'' sensation in the chest and back.
But because they often produce no symptoms until they leak or rupture, aneurysms can be difficult to detect. Thoracic aneurysms are often picked up through routine chest X-rays, which may reveal the size of the aneurysm and how much of the aorta is involved.
An echocardiogram (an ultrasound examination of the heart) may then be done. Usually, however, if a thoracic aortic aneurysm is found or suspected, an aortagram involving the injection of a radiopaque dye is needed to determine precisely its size and location.
When an examining doctor discovers signs suspicious of an abdominal aneurysm, an abdominal X-ray or ultrasound exam may reveal its size and location. More advanced tests, like a CT scan and MRI, are usually included in the diagnostic workup.
Some vascular specialists recommend that ultrasound examinations be used to screen people at high risk of developing abdominal aneurysms. Anyone found to have narrowed carotid arteries (leading to the brain) should also be checked for a possible aortic aneurysm.
People found to have small aneurysms should be monitored regularly using modern imaging techniques as well as physical examinations. Contributing factors, like high blood pressure, should be treated.
But once an aneurysm enlarges beyond two inches in diameter (the aorta is normally three-quarters of an inch to one inch wide), the risk of rupture begins to rise and surgery is likely to be recommended to repair it.
To repair an aneurysm, a flexible tube is usually grafted to the aorta to replace the damaged segment. The surgery itself can be risky, especially for people with serious atherosclerosis.
In a still-investigative approach that is similar to balloon angiography, a collapsed graft is introduced through the main artery in the leg and passed up to the weakened area of the aorta, where it is expanded and held in place with metallic supports.
If this new technique proves to be an effective alternative to abdominal surgery, it could make repair of abdominal aneurysms much simpler and safer than it is now.
New York Times
by CNB