Abdominal aortic aneurysm

Question 1

Definition of ‘aneurysm’

Answer 1

Local dilatation of an artery with an increase of diameter 50% or more

Question 2

Normal diameter of abdominal aorta in males and females

Answer 2

Males: less than 3cm
Females: less than 2.5cm

Question 3

Risk factors for AAA (8)

Answer 3

Male sex
Age >50
Family history
Genetic conditions (Marfan, Ehlers-Danlos, Takayasu)
Smoking (>90% with AAA have smoked)
Hypertension
Coronary artery disease
Diabetes

Question 4

Histopathology of AAA in

1. Tunica media and intima
2. Tunica adventitia

Answer 4

1. Foam cells, cholesterol, calcifications, thrombosis, ulcerations and rupture
2. Inflammatory infiltrate

Question 5

Most common location of AAA

Answer 5

Below the kidneys (85%). The rest are at or just above the kidneys.

Question 6

Indications for surgery

Answer 6

1. Diameter (>5.5cm males, >5.0cm females)
2. Symptoms (higher risk of rupture)
3. Rapid increase in size

Otherwise treat conservatively with smoking cessation, surveillance and BP + lipid control.

Question 7

Classic triad of ruptured AAA

Answer 7

1. Tearing abdominal pain
2. Hypovolaemic shock, syncope
3. Pulsatile abdominal mass

The risk of mortality is 85-90%

Question 8

Target systolic blood pressure range during resuscitation from ruptured AAA

Answer 8

60-80mmHg

Question 9

Other (rare) complications of AAA (3)

Answer 9

1. Peripheral embolisation
2. Acute aortic occlusion
3. Fistula (aortocaval, aortoduodenal)