December 20, 2010
How a Torn Aorta Can Do Lethal Damage
By DENISE GRADY

The death of the veteran diplomat Richard C. Holbrooke last week shocked Americans and his many colleagues around the world. Mr. Holbrooke, 69, was a larger-than-life figure, a fearless and robust man who was apparently struck down without warning.

He became ill on a Friday, and was dead by Monday. According to government officials, the cause was a tear in his aorta, the artery that carries blood from the heart to vessels that feed the rest of the body.

Mr. Holbrooke underwent 21 hours of surgery from Friday to Saturday to repair the damage, and then another seven-hour operation on Sunday, all at George Washington University Medical Center in Washington. But no amount of surgery could save him.

Aortic tears may be unfamiliar to most people, but they kill at least 2,000 Americans a year, and possibly more, because some of the deaths may be mistakenly attributed to heart attacks. Tears are more common in men than in women, and most likely in people from 40 to 70. Their causes include uncontrolled high blood pressure, atherosclerosis and a genetic tendency to have weak tissue or an abnormal valve in the aorta. There may be no warning signs before the tear occurs.

The aorta is the biggest artery in the body, more than an inch wide in some spots. It has three layers; most tears start in the innermost one. Blood can then force its way into the tear and separate the layers, or peel them apart — a type of damage called aortic dissection.

A flap and a “false channel” can form inside the aorta and impede blood flow. And the pressure from the blood can keep enlarging the tear and the flap. If the tear goes all the way through and the aorta ruptures, death can be almost immediate. That did not happen to Mr. Holbrooke, a spokeswoman said.

Tears are often — but not always — associated with aneurysms, which are bulging, weakened areas in the artery wall. High blood pressure may contribute to both problems.

It is not known whether Mr. Holbrooke had either of those conditions. His family has not been available for interviews, and his doctors were not given permission to speak to a reporter.

Surgeons not associated with his case said Mr. Holbrooke most likely had the most common type of tear, which occurs in the ascending aorta, the beginning of the vessel where it emerges from the top of the heart.

In their simplest form, such tears can be repaired “fairly easily,” said Dr. Timothy J. Gardner, a spokesman for the American Heart Association and a heart surgeon who is medical director of Christiana Care’s Center for Heart and Vascular Health in Newark, Del.

Dr. Gardner did not know the details of Mr. Holbrooke’s case, but he said, “We have to infer that he had a complicated aortic dissection where one or more of the branches of his aorta were involved and/or the tissue damage and the hemorrhage were extensive and very difficult to deal with.”

In that situation, he said, “it can be a really challenging surgical procedure.”

Dr. Robert Michler, surgeon in chief at Montefiore Medical Center in the Bronx, said that if he is in the operating room in the middle of the night, he is very likely to be repairing a torn aorta. Patients tend to show up with symptoms at night.

“Exactly why that is we don’t know,” he said.

A common symptom is sudden, severe pain in the chest, back or neck. Some people even say they feel a tearing or ripping sensation. Others have no pain. Some have shortness of breath, cold legs, abnormal pulses in their limbs or stroke symptoms like weakness or paralysis. Sometimes blocked circulation causes organs to fail.

The variation in symptoms can make it hard for doctors to figure out what is wrong and lead them to mistake the problem for a heart attack, collapsed lung or ulcer.

Delays in diagnosis can be deadly, because tears in the ascending aorta need emergency surgery. Some people die so quickly they never even make it to the hospital. Among those who do reach the hospital, if the condition is not diagnosed and treated within 48 hours, half will die.

From 80 to 90 percent survive surgery, which involves cutting out the damaged part of the aorta — several inches’ worth in most cases — and replacing it with a tube made of a synthetic material. The aortic valve may also need to be repaired or replaced, and coronary arteries may need to be bypassed.

The operations are long and complicated; the heart has to be stopped and the patient must be hooked up to a heart-lung machine that takes over the jobs of pumping blood and oxygenating it.

“You just operate until you’re done,” said Dr. Loren F. Hiratzka, a cardiothoracic surgeon and the medical director for cardiac surgery at Bethesda North and Good Samaritan hospitals in Cincinnati. “It’s not unusual to spend four to eight hours in there.”

A 21-hour operation, like the one Mr. Holbrooke had, can only be described as “heroic,” Dr. Hiratzka said, adding: “If they were in the operating room for 21 hours, I can’t imagine what they were running into. Sometimes it’s like you’re trying to repair wet tissue paper. The layers of the aorta just get shredded. The layers themselves can become very friable and hard to put back together.”

Sometimes, he and other surgeons said, the tissue is so weak that it will not hold a stitch, and they spend hours and hours sewing and trying to stop the bleeding.

In some cases it may be a genetic disorder that makes the tissue fragile and the aorta prone to tearing. Certain genetic conditions, like Marfan’s syndrome, are known to predispose people to these problems, but researchers think there are other mutations, not yet identified, that may also play a part.

Abnormalities in the aortic valve can also lead to tears. In most people, the valve has three leaflets that open and close to regulate blood flow, but in some it has only two — which can cause blood to squirt at the wall of the aorta in a jet spray, like water from a partly blocked hose. The spray can gouge pits in the artery wall.

“I have some extraordinary pictures of an aortic wall I removed from a patient with an aneurysm that showed moonlike craters in the wall of the aorta, where the aorta had been injured and tried to heal itself,” said Dr. Michler, the surgeon in chief at Montefiore. “It had happened in half a dozen places.”

CT scans and X-rays can detect aneurysms and identify people who are at risk for tears or ruptures, Dr. Michler said. If an aneurysm is developing, doctors can monitor it and operate if it gets too big. But it is not known whether Mr. Holbrooke had had X-rays or CT scans, or any reason to have had them.

Some experts believe that anyone with an aortic aneurysm or tear is likely to have some underlying genetic disorder. So whenever a patient has an aortic aneurysm, Dr. Hiratzka said, it is important for the immediate family — siblings, children and parents — to be tested for similar problems.

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