When is surgery recommended for the treatment of abdominal aortic aneurysm?

Whether surgery is a good idea, and when it should be done, depend on two questions:

• How high is the risk that the aneurysm will suddenly rupture within the next few years?
• What risks does preventive surgery involve?

Doctors who recommend abdominal aorta aneurysm surgery must inform you of your right to a second medical opinion. That means that you can have an appointment with a different specialist to help you decide whether or not to have surgery. You will not have to pay for the appointment.

A rupture is a life-threatening medical emergency that requires immediate surgery at the hospital. About half of all people who have a sudden rupture die shortly afterwards. These are the main factors that make a rupture more likely:

• In men: The aneurysm is more than 5.5 cm in diameter.
• In women: The aneurysm is more than 5 cm in diameter.
• The aneurysm has grown quickly: more than 0.5 cm in six months or more than 1 cm in one year.
• The aneurysm is causing symptoms such as pain in the back, stomach, or sides.

Aneurysm surgery can save lives. But it can also can lead to serious complications, especially lung complications and damage to the heart. The implanted piece of artificial blood vessel may become infected. The surgery may even lead to death, for example due to circulatory collapse. The risk of complications is determined by various factors. One of these is the patient’s general health. For instance, the surgery is riskier for people who have cardiovascular disease. Sometimes further surgery is needed shortly after surgery or at a later date.

Because of this, doctors estimate the individual risk of complications. Reasons not to have preventive surgery include the following:

• The person has other serious conditions, such as severe heart disease.
• Their general health is so poor that a procedure seems to be too risky, for example due to old age and associated problems.

Doctors recommend monitoring an aneurysm if no surgery is performed on it: Regular check-ups can help to find out whether the aneurysm is growing and whether the risk of rupture is increasing. Preventive surgery can be reconsidered if necessary. These checks are usually done using ultrasound scans. How often they need to be done is mostly based in the size of the aneurysm: Small aneurysms are checked less often than big ones.

These check-ups can help give some people a feeling of security. But for many others it is distressing to be living with the thought that they are at risk because of the aneurysm.

Besides the check-ups, doctors recommend having other medical conditions like high blood pressure or high blood lipid levels treated. Anyone who smokes is advised to quit.

Two techniques can be used to operate on an aneurysm:

• Open surgery through an abdominal incision (cut)
• Endovascular surgery with a catheter through a small cut or puncture in the groin

Before the procedure starts, the abdominal aorta and the aneurysm are viewed in detail using imaging, most often with computed tomography. This is important for planning the surgery: This examination is used to decide which surgical technique is an option and whether there is a suitable graft that can be implanted, or how big it needs to be. Computed tomography involves radiation and may include the use of a contrast agent.

Doctors prefer the endovascular procedure if it is medically possible. In Germany, about 80 out of 100 patients have open surgery, and 20 out of 100 have endovascular surgery.

This is done under general anesthesia. First, a cut is made in the abdominal wall. The doctors interrupt the flow of blood in the aorta by clamping it above and below the aneurysm. They cut the aneurysm open and implant a plastic tube (graft) there. It is sewn into place. Then the doctors wrap the vessel wall of the opened aneurysm around the graft and stitch it together tightly. After that, the clamps are removed and the blood is allowed to flow again.

This procedure lasts about three hours. Afterwards, you are first taken to the intensive care unit for about two days. You usually need to stay in the hospital for about one or two weeks in total. It can take several weeks or months until you are ready to get back to your normal everyday life. Check-ups about every five years are recommended after surgery.

Open surgery is often not suitable for people who also have other serious medical conditions, for instance affecting the cardiovascular system, the airways or the kidneys. The procedure is too dangerous then.

In the endovascular procedure, the doctor guides a catheter into an iliac artery in your groin region. The tip of the catheter carries a stent, with is a tube of mesh wire that is covered in plastic.

The tip of the catheter is then pushed forward along the artery with the stent until it reaches the aneurysm. There the stent expands and it is pressed against the interior wall of the aorta. The catheter is then pulled out. To position the stent in the right place, x-ray imaging using a contrast agent shows the aorta during the procedure.

Because the abdominal aorta branches off at the legs, this procedure is repeated from the other side of the groin, and then both stents are connected. The blood then flows through this compound stent. Over time, the ends of the stent grow into the wall of the blood vessel. This puts less pressure on the vessel wall, lowering the risk of the aneurysm getting bigger or rupturing.

This procedure is typically done using a general anesthetic. You have to stay in the hospital for an average of one week afterwards. It may be necessary to stay in the intensive care unit for a brief time for more complex procedures. It can take a few weeks to fully recover.

After the operation, the stent graft is checked to make sure that it is in the right position, doesn't leak and is not bent. Experts recommend having check-ups for the rest of your life: After a first check-up about one month after the procedure, additional examinations follow, but less often, for example every one, three or five years. The stent graft is often checked using computed tomography (CT), which involves radiation. Sometimes ultrasound is used instead.

Endovascular surgery isn’t always possible. It depends on certain characteristics of the aorta and where exactly the other blood vessels branch off. There also needs to be a suitable stent graft available with the right shape and size.

Although endovascular surgery is less invasive than open surgery, it doesn’t offer any improved chances of survival over the long term. Compared to open surgery, it is also more likely to be followed by further surgery and more check-ups.

Endovascular surgery is an option for older people if the risks of open surgery are too great – for instance, because they have a serious heart, lung or kidney disease.

But even then endovascular surgery may be too risky. One study involving men whose health didn't allow for open surgery suggests that they don't benefit from endovascular surgery. The same number of men had died within the next few years, regardless of whether they had endovascular surgery or chose not to have any surgery.

Both open surgery and endovascular surgery can lead to serious complications. Some people also die as a result of this surgery. The risk of dying within 30 days of surgery is higher in people who have open surgery than it is in people who have endovascular surgery. Various studies show that over the long term the same number of men die after both procedures. That may also be true for women, but there is not any good-quality research on this for women.

Surgery can also cause other complications, such as a stroke or lung problems. It may damage the heart muscle or affect the functioning of the kidneys. Surgery may also have a temporary effect on your sex life. Like all operations, the surgery is also associated with risks such as inflammations and wound healing problems.

Compared to endovascular surgery, open surgery is typically associated with more blood loss. It also leaves behind a larger scar. Sometimes an incisional hernia develops near the surgical scar and further surgery is needed. Another procedure (usually a minor procedure with a catheter) may be necessary for other reasons. For example, the artificial artery (graft) may become closed off following open surgery.

And after endovascular surgery, the stent graft may slip, become clogged or leak. Additional surgery may also be needed if it wasn’t possible to position the stent graft properly. The iliac artery may be injured while the catheter was guided along it. Compared to people who have open surgery, people who have endovascular surgery are more likely to need further surgery.

The table below shows how the two procedures differ in terms of how often the possible complications are. Please note, though: Abdominal aortic aneurysms are more common in men than in women. For this reason, most studies are on the treatment of men only. There are no good-quality studies on the two procedures in women. Much less is known about the advantages and disadvantages of the surgical procedures in women with aneurysms than in men. But experts believe that surgery in women is associated with more risks.

The information in the table is from research on men in good health generally. Women can use the figures in the table as rough guide. It is best for women to discuss any questions about the possible complications with their doctor.