Aortic disease difficult to diagnose

Jun 15 2005

Aortic disease kills nearly 15,000 people in the United States each year, but the rarity and complexity of this deadly disorder make accurately diagnosing it difficult for doctors in the health-care trenches, University of Florida researchers have found.

UF surgeons who specialize in treating the disease studied the charts of 100 patients who were transferred to Shands at UF medical center with suspected aortic ailments and found that about one-quarter of them initially had been misdiagnosed, delaying treatment for some and sending others into the operating room needlessly.

The study, which appears this month in The Annals of Thoracic Surgery, suggests many doctors who do not routinely treat aortic disease have difficulty distinguishing between the two most common culprits, an aortic aneurysm and an aortic dissection. An aneurysm is a bulge in the aorta that can rupture, while a dissection is a sudden tear in the arterial wall. "Three's Company" star John Ritter died in 2003 after suffering an aortic dissection, drawing national attention to aortic disease.

But even a slight variance in diagnosis can mean the difference between medical treatment and emergency surgery, said Thomas Beaver, M.D., a UF assistant professor of cardiovascular and thoracic surgery and the study's lead author.

"When you start talking about doing major thoracic aortic surgery on somebody, you really want to be sure what you're doing and where it started," he said. "For people who aren't as familiar with it, it can be more challenging. There are subtle nuances."

According to the National Center for Health Statistics, 14,746 people died in 2002 from either an aortic dissection or aneurysm, but most community doctors are not exposed to these disorders often enough to discern the subtleties between them, Beaver said. At Shands, where many patients are referred for aortic disease treatment, thoracic surgeons perform nearly 200 aortic procedures a year.

Increased education in medical schools and more continuing education for practicing physicians could improve how doctors diagnose aortic disease, the researchers suggest.

Prior to beginning their research, the surgeons had noticed about 30 percent of the aortic cases they received from hospitals came to them with inaccurate diagnoses, Beaver said. After Ritter's death, the surgeons decided to find out why.

Twenty-four of the 100 cases UF researchers studied had discrepancies in transferring and final diagnoses, and half of these contained initial misinterpretations of radiology tests and scans, the findings show. One patient who was rushed in for emergency surgery to repair an aortic dissection actually had a normal aorta that appeared as if it were ripping on a scan because of an imaging fluke called a pulsation artifact. The aorta moves so fast during a scan it may look like the arterial wall is tearing when it is fine, something a radiologist unfamiliar with the phenomenon may not realize, Beaver said.

But like other physicians, radiologists at a typical hospital don't see aortic dissections too often, said Tomas Martin, M.D., a UF associate professor of thoracic and cardiovascular surgery.

"The difficulty is it is an infrequent disease," he said. "It's not a common problem."

Diagnosing aortic disease also can be difficult because patients complain of "nondescript symptoms," such as chest pains, said Scott LeMaire, M.D., an associate professor of cardiothoracic surgery at the Baylor College of Medicine in Texas. Among 100,000 patients complaining of chest pains, three may have an aortic dissection, LeMaire said, so it's not the first thing a doctor may consider.

But while a patient may be able to live with an aortic aneurysm for years, a dissection requires emergency surgery if it occurs in the part of the aorta near the heart, he said.

"The outcome (of the surgery) is better than it used to be, but it is still a fairly risky surgery," LeMaire said. "Dissection is an event. There's no real way of predicting it."

Genetics could be the best indicator right now for preventing and treating aortic disease before an aortic tear or rupture, Martin said. People with relatives who have had aortic aneurysms or dissections should be examined for signs of the disease.

"It's a curable disease," Martin said. "And it's much better treated on an elective basis than on an emergency basis."