Abdominal Aortic Aneurysm

Question 1

Define an aortic aneurysm?

Answer 1

Dilatation of ALL the aortic layers to 150% of its original diameter (In an AAA that’s > 3cm)

Question 2

What commonly causes an AAA? [3]

Answer 2

Degenerative Disease
Connective Tissue Disorders (Marfans)
Sometimes Infection (e.g. Mycotic Aneurysm)

Question 3

What are the risk factors for an AAA? [5]

Answer 3

Old Age - Male - Smoking - Hypertension - FH

Question 4

How are asymptomatic AAAs found? [2]

Answer 4

By screening programs

On incidental imaging

Question 5

What screening programs are in place for AAA? [1]

Answer 5

In England every man gets an abdominal ultrasound at 65 yrs to detect AAA

Question 6

What are the symptoms of a symptomatic AAA:
Impending rupture [2]
Ruptured [4]

Answer 6

Impending Rupture: Increasing back pain & abdominal tenderness
Ruptured:
- Abdo/back/flank pain
- Painful pulsatile mass
- Haemodynamic Instability (unstable BP, can be single episode or progressive in nature)
- Hypoperfusion of the lower limbs

Question 7

Some AAAs present abnormally, what are some atypical features [5]

Answer 7

Distal Embolisation
Aortocaval fistula
Aortoenteric fistula
Ureteric Occlusion
Duodenal occlusion

Question 8

What investigation would be used to assess the AAA & plan surgery? [2]

Answer 8

CTA

MRA

Question 9

At what size do we offer repair? [1]

What is the underlying explanation for this number?

What is another indication for surgery?

Answer 9

5.5cm

The risk of rupture is related to aneurysm size, only 2% of aneurysms measuring less than 4cm in diameter will rupture over a 5 year period. This contrasts with 75% of aneurysms measuring over 7cm in diameter.

Symptomatic aneurysms are an indication for surgery other than increasing size above 5.5cm

Question 10

What are the types of repair we can give? [2]

Answer 10

EVAR and open repair

Question 11

How can AAA repair ‘fail’? [2]

Answer 11

An endoleak [1] where blood is still reaching the aneurysm sac from somewhere. [1] This is usually very minor and can be monitored for years before it needs intervention

Question 12

Describe EVAR and OR [6]

Answer 12

Endovascular (EVAR):

• Local Anaesthetic
• Small groin puncture, pass up through iliac arteries
• Place stent through aneurysm sac

Open (OR):

• General Anaesthetic
• Open abdomen & aneurysm sac
• Remove sac contents and sew in plastic tube in place of dilated section of aorta