Abdominal Aortic Aneurysm

1. What is abdominal aortic aneurysm?

Abdominal aorta is the large blood vessel in the abdomen which supplies blood to all the internal organs in the abdomen ( kidneys, intestine, spleen, liver etc). It also divides into two branches which eventually supplies blood to both the legs.

A balloon-like bulging of this artery is called abdominal aortic aneurysm. The bulge occurs due to a weakening in the wall of the abdominal aorta. This weakened blood vessel is at risk of rupture, which is a life-threatening event.

2. What are the symptoms of abdominal aortic aneurysm?

The AAA usually does not have any symptoms till very late (i.e., when they rupture). A few patients have pain in their belly (abdomen), the back or in both legs. Some patients (esp thin patients) can feel a pulsating swelling in their belly. 

When AAA ruptures, the patient may have the following symptoms

  • Pain abdomen – sudden onset 
  • Feeling giddy 
  • Fainting episodes
  • Shortness of breath
  • Nausea and vomiting

3. What are the causes of AAA?

Atherosclerosis and its risk factors

  • Smoking
  • Hypertension (High BP)
  • Diabetes
  • Increased blood cholesterol 
  • Obesity
  • Kidney disease (‘Chronic kidney disease’)
  • Family history

Vasculitis (inflammation in the blood vessel wall)

Some inherited conditions – Patients with Marfan’s syndrome and Ehlers-Danlos syndrome. Although such patients have a higher risk of thoracic aortic aneurysm/dissection some of these patients may develop AAA.

4. What are the tests used to diagnose AAA?

Ultrasonography – This is a simple, quick and painless test to diagnose AAA. 

CT angiography –  After diagnosing with ultrasonography and in patients in whom a treatment is considered, a CT angiography is performed. This test is a CT scan done by injecting the dye (contrast) through the vein to assess the aneurysm with clarity. The size, relationship of the aneurysm with adjacent important arteries (those supplying the kidneys, intestines) are assessed more clearly using a CT angiography

CT Angiography showing the Abdominal aortic aneurysm

5. What are the treatment options for AAA?

Surgical – In open surgical technique, a cut is made in the tummy and a graft is sewed into the bulging segment of the abdominal aorta.

Endovascular aneurysm repair – In this procedure the Interventional radiologist makes a small incision in both the groins. Small tubes (catheters) are advanced under x-ray guidance into the segment of the abdominal aorta with the aneurysm. A graft is then placed within the aneurysm thereby treating the disease.

EVAR (Endovascular Aneurysm Repair) Case - Angiograms before and after treatment

6. How can AAA be prevented?

A healthy lifestyle is important in preventing risk factors of Abdominal aortic aneurysm (risk factors of Atherosclerosis). Refer Q & A 8 in the Peripheral vascular disease page

7. Is there a role for screening in AAA?

Screening plays an important role in early diagnosis of AAA. (A Screening test is done to detect a disease in a person who does not have any symptoms of the disease). The USPSTF (US Preventive Services Task Force) recommends a one-time screening test in ‘men’ aged between 65 and 75 who smoke or have a history of smoking. 

Screening test is an abdominal ultrasonography, a quick and painless procedure to detect AAA

8. What if AAA is detected on screening?

If an aneurysm is detected in a patient without any symptoms, the decision to treat (surgically/endovascular) will depend on the diameter of the aneurysm. 

Aneurysms measuring less than 5cm are usually followed up closely. Patients with aneurysms measuring more than 5 cm are usually offered treatment.