An abdominal aortic aneurysm (AAA) is an abnormal dilatation of the abdominal aorta due to weakness in the vessel wall. AAAs are usually asymptomatic but can cause back pain. Risk factors include age, hypertension, smoking and family history. Large AAAs (>5.5cm diameter) have a high risk of rupture and require surgical repair via open surgery or endovascular aneurysm repair (EVAR) to exclude the aneurysm and prevent rupture. Ruptured AAAs have a mortality rate over 80% and are a major cause of death in older men.

2.  2cm width
 4 main parts
 Many branches
 Bifurcation: ~L4

3.  Abnormal localised dilatation of a blood
vessel due to weakness of the vessel wall
 Most commonly abdominal aorta
 Usually asymptomatic
› May have back pain
 Often discovered incidentally
› NHS AAA screening programme

5.  Men > women
 Increased age
 PMH:
› Hypertension
› Hypercholesterolaemia
› Atherosclerosis
› Marfan’s syndrome
 FH:
› Aortic aneurysm

6.  HISTORY
› Abdominal or back pain
› Family history
› Risk factors
 EXAMINATION
› Palpation of abdomen

7.  Mortality >80%; 50% don’t reach hospital
 13th
commonest cause of death in UK
 12,000 deaths/year in UK
Source: BHF Factfile 1, 2008
AAA Diameter (cm) Annual Rupture Rate
4 - 5.4 0.5 – 1.5 %
5.5 - 5.9 5 – 15 %
6 - 6.9 10 – 20 %
7 - 7.9 20 – 40 %
> 8 30 – 50 %

8.  Presentation:
› Pain.
 Thoracic: chest
 AAA: severe back pain, often radiates to groin
› Abdominal tenderness & pulsatile mass
› Shock:
 Cold, clammy
 Tachycardia
 Hypotension
› Syncope
› Vomiting (haemoptysis)
 Emergency surgery

9.  No effective medical treatment
› Can target cardiovascular risk factors
 Only operate if risk of rupture greater
than risk of surgery
 >5.5cm
 More if higher risk to surgery due to co-
morbidities
 Otherwise re-scan at regular intervals

10.  Longitudinal midline
incision
 Aorta clamped above
and below aneurysm
 Aneurysmal part of aorta
replaced with artificial
graft
 4-5hrs

11.  Lower mortality, more expensive
 Graft inserted through femoral artery
 X-ray used to guide positioning
 Stent expands to size of normal aorta
above and below aneurysm
 Requires ‘neck’ below
renal arteries to
attach stent graft
 2-3hrs
http://www.youtube.com/watch?
v=j9aK2ECcFEY

12.  Renal failure
 Emboli
 MI
 Graft infection

13.  Aneurysm = localised dilatation of blood
vessel
 1/15 men over 65, 1/35 women
 Rupture has > 80% mortality
 Surgical repair has ~5% mortality (varies)
 Aneurysm >5.5cm  surgery
 Open repair, EVAR