In the United States, upwards of 200,000 people are diagnosed annually with an abdominal aortic aneurysm (AAA). An AAA is an enlarged, weakened area in the lower part of the aorta—the main artery that carries blood from your heart to the rest of your body.
Treatment for this type of aneurysm depends on its size and how quickly it’s growing. Traditional open surgery was once the gold standard for repairing an AAA, but today, a growing number of physicians favor a much less invasive technique known as endovascular aneurysm repair (EVAR).
What is an AAA?
Aortic aneurysms most commonly occur in the abdomen. They can be insidious, often growing silently for years without causing symptoms. Then, when AAAs expand past a certain point, they can rupture, resulting in life-threatening bleeding. The larger the aneurysm, the more likely it is to burst.
A rupture—which is marked by stabbing pain in the back or near the navel, loss of consciousness, sweating, dizziness and nausea or vomiting, among other symptoms—is a medical emergency.
An AAA can be discovered during a routine physical exam when your healthcare provider feels your belly, assuming the area is not overly insulated by fat. Sometimes it’s an incidental finding from an imaging test for an unrelated health issue, such as a kidney stone. Men are more likely to have an AAA than women.
Having high blood pressure, high cholesterol, and other risk factors for heart disease, including diabetes and obesity, also increase the likelihood of developing this type of aneurysm. Other risk factors include advancing age and certain genetic factors. In fact, those with a close relative who’s had an AAA are 12 times more likely to develop one themselves.
Smoking also ups the risk for an AAA. The U.S. Preventive Services Task Force recommends that men aged 65 to 75 who have ever smoked undergo a one-time ultrasound to screen for this type of aneurysm.
When is it time to treat?
“If the aneurysm is larger than 5 centimeters, we begin to get concerned that it could leak and rupture,“ explains James Benner, MD, chief of cardiac surgery at Trident Health in Charleston, South Carolina. Physicians typically take a watch-and-wait approach until then, although any abrupt growth may also suggest the need to treat sooner rather than later, he adds.
The goal is to stay one step ahead of the AAA so it doesn’t burst. “About 1 millimeter of growth per year is acceptable,” says Dr. Benner. “We monitor its growth so that we won’t miss the window of opportunity.”
What does EVAR entail?
Years ago, most AAA procedures were traditional open surgeries, Benner says. But improvements in techniques and technology have led to much greater use of EVAR. Now, EVAR represents about half of all AAA procedures performed in the U.S. It’s most commonly used to repair AAAs, but can also help repair other types of aneurysms, including thoracic aneurysms.
During EVAR, an interventional physician—such as an interventional radiologist or vascular surgeon—makes an incision in one or both of your groin (femoral) arteries. Using X-ray and dyes for proper visualization on a TV monitor, they will then thread a thin tube (catheter) to the AAA. Next, a stent or small mesh tube covered with a thin polyester fabric is delivered through the catheter, where it is placed and positioned within the aneurysm. These stents comprise about three or four parts and are much larger than those used to prevent heart attacks.
“We put it together in the aorta like an erector set, so the stent can direct blood flow through the aorta,” Benner says. “This decreases the pressure on the aortic wall that could lead to rupture.”
What are the benefits of EVAR?
There are many advantages to treating AAA via an endovascular approach. For starters, individuals who undergo a more invasive open AAA surgery typically stay in the hospital for five nights and are placed on restricted activity for four to six weeks, says Benner. By contrast, your EVAR hospital stay is shorter and your recovery is quicker. Research shows the average stay for EVAR is 3.5 days, but many patients go home after one or two days, according to Benner. Following the procedure, they’re asked to take it easy for another four or five days, he adds.
The EVAR procedure itself is faster, too. It usually takes about an hour or two to complete, and can be done using regional anesthesia, conscious sedation—where you are awake, but not aware—or sometimes general anesthesia. Open surgery takes about three hours and always involves general anesthesia.
When performed by a skilled interventional physician on an appropriate candidate, EVAR is a safer procedure with fewer complications than open surgery—especially in the 30 days following the surgery, which is a well-documented high-risk period. In one large study published in the New England Journal of Medicine in 2015, risk of dying in the 30 days after EVAR was less than one-third of what was seen following open repair. Researchers also noted fewer medical and surgical complications and a shorter hospital stay among EVAR patients.
That said, EVAR and open surgery for AAA have similar long-term outcomes since EVAR is more likely to require an additional repair. Essentially, open surgery is a permanent fix, while EVAR may require tweaks from time to time. If you undergo EVAR, you will need to be followed closely for years to make sure the stent does not shift.
“If there is a change in position, we may need to re-position the stent,” Benner says. If you move to a new area, make sure you connect with an interventional physician who will monitor your health and make sure your stent is still in place, he adds.
What to know before EVAR
Open surgery is still warranted if your surgeon can’t access your aorta through your groin. “If both of your groin arteries are blocked, we can’t get the device where it needs to go,” Benner says. In addition, some AAAs develop where the aorta branches out to the kidney. If it’s too close to the renal arteries that carry blood from the heart to the kidneys, the AAA may require traditional surgery.
If your healthcare provider suggests an endovascular approach, they will recommend you get screened by a cardiologist to make sure you are healthy enough to undergo the procedure. This involves blood tests and other diagnostic screenings. If you’re a smoker, it’s also important that you stop smoking before your procedure.
Not every interventional physician or center can or should perform EVAR. New guidelines suggest that it should be limited to centers that do at least 10 EVAR procedures every year. They should demonstrate a low risk of death and a low likelihood that the procedure has to be converted to an open surgery while it’s still in progress, which is a complication that can occur.
The guidelines also state that EVAR is preferred over open surgery if the aneurysm bursts—as long as it is feasible. “When the artery has ruptured, the outcome is never as good,” Benner says.
If your physician suggests EVAR as a treatment for your aneurysm, be sure to ask these questions:
- Why do you recommend EVAR over the traditional surgical approach?
- What are the risks of each procedure for me?
- What type of follow-up is required?
- How will I know if the stent has shifted?
- How many endovascular procedures do you perform each year?
- What is your center’s safety record for these procedures?
Together, you can decide if EVAR is the right treatment option for you.
