Sunday, June 20, 2021

A New Treatment Approach for Deadly Aneurysms

An aortic aneurysm is a stealthy, often silent vascular abnormality that can be deadly if left untreated. In most cases, people with this condition have no idea they have a balloon-like bulge in the wall of the aorta, the largest artery in the body, which carries blood from the heart down through the torso to the limbs and organs.

An aneurysm is a weakness in the arterial wall, and if it is not diagnosed, it can grow until it bursts, causing life-threatening internal bleeding. If this happens, it may be difficult for a patient to get to a hospital in time for repair.  Care for patients with an aortic aneurysm, which is diagnosed in roughly 200,000 Americans annually, has improved dramatically over the years.

Repairing them once required open surgery that involved a major abdominal incision, several days in the hospital, and several months for recovery. But now, most repairs are much easier on the patient. Raul Guzman, M.D., a vascular surgeon and chief of Yale’s Division of Vascular & Endovascular Surgery, said:

“We treat at least 80% of aortic aneurysms with minimally invasive approaches — and that includes some of the most complicated ones.”

He and colleagues Cassius Iyad Ochoa Chaar, M.D., M.S., and Naiem Nassiri, M.D., use a technique called endovascular aneurysm repair (EVAR) that can be performed through a small needle puncture in the arteries located near the top of the thigh rather than through a large incision in the abdomen.

Basically, a thin tube called a delivery catheter is inserted into the artery, and an expandable graft is placed within the aorta to reinforce it. The stent graft can then be expanded to seal itself in place and prevent the effects of pressure on the weakened aortic wall.

Reaching difficult areas of the body

The aorta is the body’s largest blood vessel. It is shaped like a cane with the short end leaving the top of the heart and the long end going down past the chest into the abdomen. Aneurysms are more common in the abdominal section, but also can occur in the chest. Thoracic aortic aneurysms are the ones most likely to have genetic associations, while abdominal aortic aneurysms are more likely to be related to environmental, or lifestyle, factors including smoking.

Thoracic aortic aneurysms are the ones most likely to have genetic associations, while abdominal aortic aneurysms are more likely to be related to environmental, or lifestyle, factors including smoking. (Image: via pixabay / CC0 1.0)

EVAR, first performed in the 1990s, is now considered the standard for repair of abdominal aortic aneurysms. For those that form in the chest, thoracic endovascular aorta repair (TEVAR) is now used. Medical advances have continued to improve the tools and devices used for aneurysm repair. Dr. Guzman said:

“We’re now using third- and fourth-generation endografts. Through contributions from bioengineers and vascular surgeons, the devices we use are now more durable and easier to deploy. They have become a routine part of our practice.”

One change that has occurred over the past 10 years is that vascular surgeons are now better able to treat aortic aneurysms that involve the vessels to the kidneys and intestine. Dr. Guzman went on to say:

“There are so many technical issues that surgeons must consider when treating different types of aneurysms, such as which graft to use and how to best deliver it to the affected area. Over time, we’ve become pretty comfortable with the different grafts and determining which situations are best treated by specific types.”

Lifesaver for elderly patients

Experienced surgeons consider a variety of factors in determining which treatment approach is best, weighing factors such as the health of the patient, the size of the aneurysm, and its location along the artery. For some patients, such as those with complicated anatomy, and those who are young and healthy, traditional open surgery still may be the best option (it may perform better in the long run).

An EVAR procedure typically takes two hours or so, Dr. Chaar says. On occasion, he has done the procedure using local anesthesia, which is safer in elderly patients for whom general anesthesia can pose more risks. (Image: via pixabay / CC0 1.0)

But an important advantage for patients undergoing EVAR and TEVAR is that vascular and cardiac surgeons are able to work together in a “hybrid operating room,” where they can transition to an open operation, if necessary. (Yale New Haven Hospital has two full-time hybrid operating rooms, for instance.) Because of this, Dr. Chaar says he has been able to make minimally invasive surgery available to more patients over time, including emergency patients with ruptures and elderly patients in their 90s who are at higher risk for complications with major surgery.

An EVAR procedure typically takes two hours or so, Dr. Chaar says. On occasion, he has done the procedure using local anesthesia, which is safer in elderly patients for whom general anesthesia can pose more risks. While an open operation would require several days in the hospital, including time in an intensive care unit, patients having EVAR are often able to return home the next day.

One patient’s experience

One of Dr. Chaar’s patients was Steve Downing, a retired Yale pathologist who was approaching his 90th birthday when he was diagnosed with an abdomina­­­­­l aortic aneurysm measuring 7.2 centimeters. (It’s estimated that an abdominal aneurysm over 5.5 centimeters, about the diameter of a soda can, has a 2 percent chance of rupture within a year.)

Dr. Downing was familiar with aneurysms, but he was hesitant about surgery, even though it would be an elective minimally invasive procedure, saying:

“I was thinking because of my age, I should ride it out and see what happened.”

Then, he started to feel discomfort in his belly, and a CT scan in the emergency department (ED) showed a potential leak from the aneurysm. A conversation with his primary care doctor convinced him to undergo the aneurysm repair. Dr. Chaar fixed the aneurysm, saying:

“We put in the stent and an additional cuff higher up to get a good seal. It was challenging, but it went smoothly.”

Several months later, Dr. Downing says he feels as good as he did before the operation:

“It was ridiculously simple and easy from my perspective. Virtually no discomfort. There was no interference to any other organ system, and the flow of blood to my legs is as normal as it always has been.”

Should you be screened for aortic aneurysm?

While screening and awareness of potential risk factors can help (see below), many aneurysms are found incidentally during CT scans, ultrasounds, or X-rays to assess for another problem. A small percentage of people have symptoms such as abdominal or back pain. Dr. Chaar said:

“Sometimes, if the aneurysm is big, a doctor can feel it when they’re doing an exam.”

The U.S. Preventive Services Task Force (USPSTF) recommends men aged 65 to 75 years who have ever smoked get a one-time ultrasound screening for abdominal aortic aneurysms (even if they have no symptoms) and selective screening for men in this age group who have never smoked. In 2018, the Society for Vascular Surgeons went a step further, recommending the same screening criteria for women who have a history of tobacco use.

In 2018, the Society for Vascular Surgeons went a step further, recommending the same screening criteria for women who have a history of tobacco use. (Image: via pixabay / CC0 1.0)

Yale Medicine Vascular surgeons encourage anyone who smokes or has a family history of aortic aneurysms — and anyone who is concerned for any reason — to talk to their doctor about the possibility of screening.

One strategy for preventing aneurysms

Meanwhile, researchers are studying other ways to keep aneurysms from growing to sizes that will put them at risk. One direction is to study ways to decrease inflammation around the aorta with medicines, says Dr. Guzman, adding:

“The most obvious way to prevent aortic aneurysms is to get people to stop smoking.”

He went on to say that tobacco smoking accounts for about 75 percent of all abdominal aortic aneurysms, and it’s also a risk factor for thoracic aneurysms. Researchers think smoking leads to inflammation of the aortic wall, and that damages the wall and allows the artery to bulge out, adding:

“At one point, smoking rates were trending lower, and therefore the number of patients who developed aortic aneurysms was also decreasing. But now it appears that smoking rates are no longer going down, and so, unfortunately, we continue to see patient with aneurysms that could have been prevented.”

Provided by: KATHY KATELLA, Yale University [Note: Materials may be edited for content and length.]

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Troy Oakes
Troy was born and raised in Australia and has always wanted to know why and how things work, which led him to his love for science. He is a professional photographer and enjoys taking pictures of Australia's beautiful landscapes. He is also a professional storm chaser where he currently lives in Hervey Bay, Australia.
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