Abdominal Aortic Aneurysm

Question 1

Definition

Answer 1

A localised enlargement of the abdominal aorta such that the diameter is > 3 cm or > 50% larger than normal diameter.

o NOTE: normal diameter of the aorta = 2 cm

Question 2

Aetiology

Answer 2

There are NO specific identifiable causes

Question 3

Risk factors

Answer 3

o Severe atherosclerotic damage to aortic wall
o Family history
o Smoking
o Male
o Age
o Hypertension
o Hyperlipidaemia
o Connective tissue disorders: Marfan’s syndrome, Ehlers-Danlos syndrome
o Inflammatory disorders: Behcet’s disease, Takayasu’s arteritis

Question 4

Presenting symptoms (unruptured)

Answer 4

o NO SYMPTOMS

o Usually an incidental finding

o May have pain in the back, abdomen, loin or groin

Question 5

Presenting symptoms (ruptured)

Answer 5

o Pain in the abdomen, back or loin

o Pain may be sudden or severe

o Syncope

o Shock
· NOTE: degree of shock depends on site of rupture and whether it is contained

Question 6

Signs on physical examination

Answer 6

· Pulsatile and laterally expansile mass on bimanual palpation of the abdominal aorta

· Abdominal bruit

· Retroperitoneal haemorrhage can cause Grey-Turner’s sign

Question 7

Investigations (bloods)

Answer 7

o FBC, clotting screen, renal function and liver function

o Cross-match if surgery is planned

Question 8

Investigations (scans)

Answer 8

o Ultrasound - can detect aneurysm but CANNOT tell whether it is leaking or not

o CT with contrast - can show whether an aneurysm has ruptured

o MRI angiography