Abdominal Aortic Aneurysm

Question 1

What are the risk factors for an AAA. (3)

Answer 1

It is more common in patients above 60.
It is more common in men.
There may be a family history.

Question 2

What are the typical causes of an AAA. (4)

Answer 2

Atherosclerotic.
Inflammatory (due to infection, eg E coli, salmonella).
Trauma.
Congenital (eg Marfan’s, Ehlers-Danlos).

Question 3

Where do AAAs usually occur.

Answer 3

95% are infrarenal.

Question 4

What is the biggest risk associated with AAAs.

Answer 4

Rupture.

Question 5

What increases the risk of an AAA rupturing.

Answer 5

The risk of rupture increases exponentially with increasing diameter.

Question 6

What are the symptoms of an AAA. (2)

Answer 6

May be asymptomatic.

Back or loin pain (most commonly intermittent or continuous).

Question 7

What are the physical signs of an AAA. (3)

Answer 7

Pulsatile abdominal mass (if ruptured or rapidly expanding).

Patient may present with ‘Trash feet’ - dusky discoloration of the digits secondary to emboli from the aortic thrombus.

Question 8

What percentage of the population over 60 have an AAA.

Answer 8

5%.

Question 9

What symptoms does a rapidly expanding AAA cause. (2)

Answer 9

Severe epigastric pain, that radiates to the back.

Question 10

What signs are associated with a ruptured AAA. (6)

Answer 10

Pulsatile Abdominal Mass. 
Hypotension. 
Tachycardia. 
Profound Anaemia. 
Sudden Death.
Hypovolemic shock (if ruptured)

Question 11

What is the differential diagnosis for AAA pain. (4)

Answer 11

Renal colic.
Diverticulitis.
Severe lower abdominal pain.
Testicular pain.

Question 12

What signs are present in overweight patients with a potential AAA.

Answer 12

Usually none, as the aorta is retroperitoneal.

Question 13

What are some complications associated with inflammatory aneurysms.(3)

Answer 13

They may obstruct adjacent structures. (eg vena cave, ureter, duodenum)

Question 14

If a patient with haematemesis in the context of an AAA, what is the cause.

Answer 14

The haematemesis is secondary to an artoduodenal fistula.

Question 15

What are some incidental presentations of an AAA. (3)

Answer 15

On physical exam.
Plain x-ray.
Abdominal ultrasound.

Question 16

Where can AAA pain present. (5)

Answer 16

Pain location is dependent on the location of the AAA.
Central abdomen. 
Back. 
Loin. 
Illiac Fossa. 
Groin.

Question 17

What are some thromboembolic complications of an AAA. (2)

Answer 17

A thrombus within the aneurysm sac may be a source of emboli to the lower limbs.
Less commonly, the aorta may undergo thrombotic occlusion.

Question 18

What signs are present if an AAA is compressing the duodenum. (2)

Answer 18

Obstruction.

Vomiting.

Question 19

What signs are present if an AAA is compressing the inferior vena cava. (2)

Answer 19

Oedema.

DVT.

Question 20

Where do AAA rupture. (3)

Answer 20

Retroperitoneum.
Peritoneal Cavity.
Any other surrounding structures.

Question 21

What surrounding structure is a common location for AAA rupture.

Answer 21

Inferior vena cava.

Question 22

What is a complication of AAA rupture near the inferior vena cava.

Answer 22

Aortocaval fistula.

Question 23

What is an aneurysm.

Answer 23

An artery with a dilation of more than 50% of its original diameter.

Question 24

What diameter is required to diagnosis an AAA on ultrasound.

Answer 24

More than 3cm.

Question 25

What is the prevalence of AAA between men and women.

Answer 25

3:1 men:women.

Question 26

In what group are AAA less common.

Answer 26

Diabetics.

Question 27

What is the pathophysiology of AAA development.

Answer 27

Degeneration of elastic lamellae and smooth muscle loss.