An abdominal aortic aneurysm (AAA) is an enlargement of the lower part of the aorta that extends through the abdominal area.
The aorta is the main blood vessel that carries blood from the heart to the rest of the body. Like most arteries, the aorta is elastic, which allows it to be filled with blood under high pressure.
An aneurysm develops when the wall of the artery becomes weakened and distended like a balloon. Aneurysms usually are discovered before they produce symptoms, such as back pain, but like the weakened hose, they may rupture if they become too large.
A ruptured aneurysm is extremely dangerous and can cause life-threatening bleeding. Aneurysms are best corrected by an operation before this happens.
Predisposing factors for abdominal aneurysm
High blood pressure
Abdominal aortic aneurysm screening
AAA is a major health risk that may not have related symptoms until a life-threatening event occurs, such as aneurysm rupture. An abdominal ultrasound is a preventive screening tool that can be used to identify an AAA so that prompt treatment can be provided prior to aneurysm rupture.
AAA screening is recommended for the following:
Men age 55 or older with a family history of AAA
Women age 65 or older with a family history of AAA or with a smoking background
Types of Aneurysms
Men are more commonly affected by aneurysms than women.
Different types of aneurysms:
Abdominal: in an artery in the abdomen
Thoracic: in an artery in the chest area
Cerebral: in an artery in the brain
Peripheral: in the large arteries that run down the legs and behind the knees, and occasionally arms
Most aneurysms occur in the abdomen. Abdominal aortic aneurysms occur most frequently in people over age 60 and most commonly at a point in the aorta just below the level of the kidneys.
Most people are unaware that they have an aneurysm because, in most cases, there are no symptoms.
Symptoms may include:
When performing a physical examination, pulsating enlargement or tender mass
Pain in the back, abdomen, or groin that may be prolonged and is not relieved with position change or pain medication
A ruptured aneurysm usually produces sudden, severe pain and other symptoms such as loss of consciousness or shock, depending on the location of the aneurysm and the amount of bleeding.
A ruptured aneurysm requires emergency treatment.
Detecting an Abdominal Aneurysm
Most abdominal aneurysms are diagnosed during a routine physical examination or on X-ray when being tested for other health concerns.
Once an aneurysm is suspected, the following imaging tests may be used to determine size, location of the aneurysm, and treatment options:
Ultrasound: High-frequency sound waves, inaudible to the human ear, are transmitted through body tissues. The echoes from the sound waves are recorded and transformed into video or photographic images
CT scan: Computed tomography uses X-rays and computers to produce images of a cross-section of the body
MRI: A large magnet, radio waves, and a computer are used to produce clear pictures of the body. This procedure does not involve the use of X-rays
Angiogram: Test in which a catheter is inserted into a blood vessel and a contrast dye is injected to make the blood vessels visible on the X-ray. This is rarely used to diagnose an abdominal aortic aneurysm but may be used to aid in the treatment of an aneurysm
Treating an Abdominal Aneurysm
If you have a small aneurysm, your doctor will ask you to come back every 6 to 12 months for a CT or ultrasound. These tests are used to measure the size of your aneurysm, and to review any other symptoms you may have.
If surgery is recommended, you will need a comprehensive medical evaluation prior to your surgery, which may include a stress test and cardiology visit.
The best method to repair an aneurysm depends upon several factors, including the location and shape of the aneurysm as well as the physical condition of the patient. Very large or symptomatic aneurysms require treatment.
There are two types of surgical treatments for large aneurysms:
Minimally Invasive Repair (endovascular grafting)
Open surgical repair
Endovascular Grafting (EVAR)
Endovascular means inside or within a blood vessel, which is exactly how a small fabric tube that has metal stents attached to the fabric, called a stent-graft, is introduced into your body and moved into place.
First, small incisions are made in each groin to get to arteries that carry blood from the aorta. The surgeon then moves the stent-graft up through these arteries until it is opened inside the diseased portion of aorta. The stent-graft reinforces the weakened part of the vessel from the inside and creates a new channel through which the blood flows, eliminating the risk of rupture.
Using X-ray guidance, the surgeon places the graft in the area of the aneurysm. The graft is then opened up inside the aorta and held in place with metal hooks and stents rather than stitches. By tightly sealing the area with your artery above and below the aortic aneurysm, the graft allows blood to pass through it without pushing on the aneurysm.
This procedure usually takes 1 to 3 hours and patients typically leave the hospital in 1 to 2 days. The timeframe to return to normal activity ranges from 2 to 6 weeks.
Like any medical procedure, endovascular repair has a risk of complications. It also involves regular routine follow-up visits with your doctor to evaluate the stent-graft. These regular follow-ups are extremely important.
The Reason for EVAR
The goals of aortic aneurysm treatment are to reduce the risk of complications from aneurysms. The major risk for untreated aneurysms is rupture, and as an aneurysm gets bigger, the risk gets greater.
There are several factors to consider when deciding to treat an aneurysm with surgery, including:
The presence of symptoms
The size of the aneurysm, in particular its diameter
How fast the aneurysm is growing, in particular rapid aneurysm growth
The development of an aortic dissection
The patient’s overall medical condition
Your doctor will consider your specific condition and needs when choosing the best treatment for you.
The procedure itself generally takes 2 to 3 hours. You will stay in the hospital 1 to 2 days, and full recovery will take about a month.
What are the Possible Risks of the Procedure?
This is generally a very safe procedure, and special precautions are taken to decrease the risk of complications. However, as with any surgical procedure, there are risks. Your doctor will discuss the specific risks and potential benefits of the recommended procedure with you.
Complications that can happen after endovascular aneurysm repair include:
Leaking of blood around the graft
The graft moving away from its initial placement
The stent breaking
Complications that are rare but serious (paralysis, delayed rupture of the aneurysm or infection)
When you meet with your doctor, please ask questions to make sure you understand the risks of the procedure, outcomes and why the procedure is recommended.
Before the Procedure?
A few days before the procedure, you may need pre-procedure tests to make sure it is safe for you to have the surgery. You may need to stop taking certain medications before the procedure. Your healthcare team will give you specific instructions to help you prepare for the procedure.
Please tell your physician if you are taking Coumadin or other anticoagulants, diuretics, or insulin.
Your physician may want to stop or adjust the doses several days prior to or on the day of the procedure, especially those listed below:
Please discuss all of your allergies with your doctor, especially those listed below:
IVP dye/contrast agent allergy
Latex/rubber products allergy
What to Bring
A family member to wait with you before the procedure
Comfortable, easy-to-fold clothing
Toiletries and any other items you would like to make your stay more comfortable. Please note, this will be kept with whoever accompanies you
A one-day supply of your prescribed medications
Do not bring any jewelry, watches, and/or valuables
After the Procedure
What to Expect After the Procedure
Your surgeon will give you specific instructions to follow after the surgery until your incision is properly healed.
You may have the following restrictions after the procedure:
Do not drive until your doctor says it is ok. This is usually 1-2 weeks after the procedure and after you have stopped taking pain medication
Do not take a bath until the incisions heal. Showers are and sponge baths around the incisions are okay 2 days after the procedure
Do not lift more than 10 pounds for 4-6 weeks after the procedure
How You Will Feel After the Procedure
As with any surgical procedure, you will feel a bit tired for a few weeks. You may develop an inflammatory response as blood stops flowing through the aneurysm. The inflammation may cause a low-grade fever (100 or 101 degrees Fahrenheit) and make you feel like you have the flu, but the symptoms will go away in several days.
You will not notice the stent itself. You should notice no difference in your ability to perform daily activities, and you should be able to get back to all of your regular activities without any restrictions.
The Results of the Procedure
Endovascular grafting produces very good outcomes. You will need follow-up visits for the stent graft, but most patients live a normal life after the procedure.
In general, patients with aneurysms should follow a healthy lifestyle that includes a balanced diet and regular exercise. Having an aneurysm increases your risk of heart disease and atherosclerosis. Along with the aneurysm repair, you should have a full evaluation to assess your risk of these other diseases.
Open Surgical Repair
This involves the surgeon making a long incision incision in the skin to open the abdomen to access the abdominal aortic aneurysm.
The segment of the aorta above and below the bulging aortic section is clamped and the aneurysm segment is opened. Tubes made out of artificial material are positioned inside the artery and sewn to the aorta above and below the aneurysm. This essentially replaces the aneurysmal segment of the aorta with an artificial one.
Open surgical repair is a proven procedure that has a good track record and acceptable risks, but it also involves a long recovery period. Average hospital stay ranges from 5 to 8 days. The time until return to normal activity ranges from 6 weeks to 3 months. As with any operation, open surgical repair has a risk of complications. You will want to discuss them thoroughly with your doctor.
What is an Endoleak?
An endoleak is a complication when some amount of blood flow still remains in the aneurysm cavity. It affects about 15-25% of patients who have EVAR.
Diagnosing an Endoleak
Imaging studies, such as CT scans, ultrasounds and MRIs, are done during and after an EVAR procedure. These tests show if the procedure was successful and if the stent graft is in place and working. They also show any leaks around the stent.
An angiogram is done at the end of the procedure, which usually allows the proceduralist to see Type I, III and sometimes Type II endoleaks. Postoperative imaging should be performed for the life of the endograft as it is possible for endoleaks to develop in a delayed fashion.
Your doctor will let you know how often you need to come in for imaging tests.
Treating an Endoleak
If you have an endoleak, you will need treatment. The first step is for your physician to determine the type of endoleak. The type of treatment you need depends on the type of endoleak you have and the size of the aneurysm sac. It is important to see an experienced endovascular aortic surgeon for treatment.
If you have a Type I endoleak, treatment should be done the right away. This may include:
Special balloon stents
Extending the stented area of the aorta by placing stents beyond the leaking end of the graft
Placing special cuffs at the end of the graft
Use of special glue-like materials to close off the graft
If the graft cannot be repaired using an endovascular technique, you may need an open repair/surgery to remove the stent graft and repair the aneurysm in standard open fashion
Type II endoleaks sometimes stop without treatment. This happens if the branches of the blood vessels that are leaking clot off and stop sending blood to the aneurysm. If this is the case, you will need imaging tests on a regular basis to watch for changes.
If the leak does not stop and causes the aneurysm to get bigger, treatment to close off the blood vessels may include:
Use of a special glue-like material to stop the bleeding
Laparoscopic techniques to tie off the blood vessels
You may need open surgery to tie off the blood vessels and repair the graft.