What is an Abdominal Aortic Aneurysm

 

Dr Walid Mohabbat
Vascular Surgeon

An abdominal aortic aneurysm is an enlargement of the lower part of the aorta that extends through the abdominal area (at times, the upper portion of the aorta in the chest can be enlarged). The aorta is the main blood vessel that carries blood from the heart to the rest of the body.

An abdominal aortic aneurysm is an enlargement of the lower part of the aorta that extends through the abdominal area (at times, the upper portion of the aorta in the chest can be enlarged). The aorta is the main blood vessel that carries blood from the heart to the rest of the body.

Since arteries are elastic and are filled with blood under high pressure, the wall of the artery may become weakened and distended like a balloon. The analogy of a bubble in a garden hose would be appropriate in describing an aneurysm. Aneurysms are usually discovered before they produce symptoms, such as back pain, but like the weakened hose, they may rupture if they become too large. Since a ruptured aneurysm is extremely dangerous, causing life-threatening bleeding, aneurysms are best corrected by an operation before this happens.

What are some predisposing factors for abdominal aneurysms?

  • Arteriosclerosis (also called atherosclerosis). This occurs when the normal lining of the arteries deteriorates, the walls of the arteries thicken, and deposits of fat and plaque block the flow of blood through the arteries.
  • High blood pressure (hypertension). This speeds up damage to blood vessel walls.
  • Disease, such as diabetes, high cholesterol.
  • Genetics or Heredity – especially if a first degree relative has had an aneurysm anywhere in the body
  • Smoking – including a history of ever having smoked in the past
  • Injury – less common
  • Infection – less common
  • Congenital defects, such as an inherited weakness in the blood vessel wall, example Marfan’s syndrome.

What are some different types of aneurysms?

  • Abdominal aneurysm — in an artery in the abdomen (mid-section)
  • Thoracic aneurysm — in an artery in the chest area
  • Cerebral aneurysm — in an artery in the brain (usually treated by neurosurgeons)
  • Peripheral aneurysm — 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. Men are more commonly affected by aneurysms than women.

What are the symptoms of abdominal aneurysms?

Most people are unaware that they have an aneurysm because in most cases, there are no symptoms. However, as aneurysms grow, symptoms may include:

  • Pulsating enlargement or tender mass felt by a physician when performing a physical examination
  • Pain in the back, abdomen, or groin that may be prolonged and 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.

How is an abdominal aneurysm detected?

Most abdominal aneurysms are diagnosed during a routine physical examination or on X-rays 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. Most commonly used initial test or screening test.
  • CT scans — computed tomography, commonly known as a CT scan, uses X-rays and computers to produce images of a cross-section of the body. Most commonly used test for planning a repair or after the repair.
  • Magnetic resonance imaging (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. Used in those patients that cannot have a CT scan.
  • Angiogram — test in which a thin tube (catheter) is inserted into a blood vessel and a contrast dye is injected to make the blood vessels visible on the X-ray. Rarely needed to plan complex repairs.

How are abdominal aneurysms treated?

Surgical repair

Very large or symptomatic aneurysms require immediate treatment. There are two types of surgical treatments for large aneurysms.

1. Open surgical repair

This involves the surgeon making an incision to access the abdominal aortic aneurysm. The diseased portion of the aorta is replaced with a graft that acts as a replacement blood vessel. 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.

2. Stent-graft in place Endovascular repair

“Endovascular” means “inside or within a blood vessel” — and that 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. This procedure usually takes 1 to 3 hours and patients typically leave the hospital in 1 to 2 days. 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 and will require CT.

Observation

If you have a small aneurysm, your doctor will ask you to come back every 6 to 12 months for a CT or ultrasound 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. This may include a stress test and cardiology visit.