Abdominal Aortic Aneurysm (AAA)


An abnormal dilation of the abdominal portion of the aorta (the major artery from the heart). 
Abdominal aortic aneurysm involves a dilation, stretching, or ballooning of the aorta. The exact cause is unknown, but risk factors include atherosclerosis and hypertension. Abdominal aortic aneurysm may be caused by infection, congenital weakening of the connective tissue component of the artery wall, or rarely, from trauma.

Abdominal aortic aneurysm can affect anyone, but it is most often seen in men 40 to 70 years old. A common complication is ruptured aortic aneurysm. This is a medical emergency where the aneurysm breaks open, resulting in profuse bleeding into the abdominal cavity. Ruptured aneurysm occurs more frequently in patients with larger (>5cm) aneurysms. Aortic dissection occurs when the lining of the artery tears and blood leaks into the wall of the artery. An aneurysm that dissects is at even greater risk of rupture.

In children, abdominal aortic aneurysm can result from blunt abdominal injury or from Marfan's syndrome.

Prevention
Avoid blunt trauma to the abdomen, atherosclerosis, and hypertension.

Symptoms

  • Asymptomatic abdominal aortic aneurysm:
  • Pulsating abdominal mass, (rhythmic throbbing)

Symptoms of Rupture:

  • Pulsating sensation in the abdomen
  • Pain in the abdomen
  • Severe, sudden, persistent or constant
  • Not colicky or spasmodic
  • May radiate to groin, buttocks, or legs
  • Pain may begin suddenly
  • Abdominal rigidity
  • Pain in the lower back
  • Severe, sudden, persistent, may radiate
  • Paleness
  • Rapid pulse
  • Dry skin/mouth
  • Excessive thirst
  • Anxiety
  • Nausea and vomiting
  • Light-headedness occurs with upright posture
  • Fainting occurs with upright posture
  • Sweating, excessive
  • Skin, clammy
  • Fatigue (tiredness or weariness) developing recently
  • Heartbeat sensations
  • Rapid heart rate(tachycardia) when rising to standing position
  • Impaired ability to concentrate
  • Shock
  • Abdominal mass

Signs and tests
Listening to the abdomen with a stethoscope  shows a "blowing" murmur over the aorta or a "whooshing" sound (bruit). Physical examination of the abdomen is performed. If a rupture is suspected, physical examination for signs of blood loss and an evaluation of lower extremity pulses and circulation are performed.

Abdominal aortic aneurysm may show on these tests:

  • Abdominal X-ray
  • Abdominal ultrasound
  • MRI of abdomen
  • CT scan-abdominal
  • Angiography of aorta