Abdominal Aortic Aneurysm

Question 1

Definition

Answer 1

Permentant aortic dilation exceeds 50% where diameter > 3cm
Typically INFRARENAL (below renal arteries), in elderly men
Most common vessel aneurysm
3 types of Aneurysms:
- true: fusiform, saccular (berry)
- false: pseudo-aneurysm
Most AAA are fusiform aneurysm not berry

Question 2

Risk factors

Answer 2

Many - Idiopathic
Conns tissue disorders -> M + ED
Smoking = BIGGEST RF
Obesity
HTN
Trauma (basically atherosclerosis)
Fx
Ageing

Question 3

Pathophysiology

Answer 3

Smooth + elastic + structural degradation IN ALL THREE LAYERS of VASCULAR TUNIC (intima, media, adventitia) with leukocyte infiltrate
- all three layers = true aneurysm
- not all three = pseudo aneurysm
Dilation = 3+ cm
Dilation with increased rupture risk 5.5cm+
Rupture = SURGICAL EMERGENCY

Question 4

Inflammatory AAA

Answer 4

Younger patients who smoke + atherosclerotic arteries, same Px + pyrexia

Question 5

Aetiology

Answer 5

Atheroma
Trauma
Infection (e.g. mycotic aneurysm in endocarditis; tertiary syphilis - especially thoracic aneurysms),
Connective tissue disorders (Marian’s, Ehlers-Danlos),
Inflammatory (e.g, Takayasu’s aortitis)

Question 6

Symptoms

Answer 6

Asymptomatic till increase rupture risk/ruptured (may be found incidentally)
SUDDEN EPIGASTRIC PAIN RADIATING TO FLANK,
PULSATILE MASS
Hypotensive
Tachycardia

Question 7

Differential

Answer 7

Acute pancreatitis
- Typically non pulsatile
- more associated GreyTurner/Cullen signs

Question 8

Diagnosis

Answer 8

FIRST LINE + DIAGNOSTIC = ABDO USS (assess aorta)
- cheap, easy, increase sensitive + specific

Question 9

Treatment

Answer 9

If non ruptured:
- Conservative = manage RF (decrease smoking, decrease BMI, statins, decrease BP)
- aSx + <5.5cm = monitor
- Sx + >5.5cm +/or expanding rapidly (1cm+/-) = SURGERY:
- Endovascular repair = stent inserted through femoral = less invasive, more post op complications
- Open surgery = fewer complications, more invasive

Question 10

Treatment (if ruptured) Also classed as a complication

Answer 10

Stabilise (ABCDE), fluids and transfusion considered then surgery:
- AAA graft surgery; replace weakened walls with graft
100% mortality if not treated IMMEDIATELY, SURGICAL EMERGENCY

Question 11

Locations

Answer 11

Most AAA occur in abdominal infrarenal aorta
Can occur in THORACIC AORTA - main culprits are MARFANS/EHLERS DANLOS + atherogenesis
Monitor with CT/MRI
Any Sx causes -> surgery straight away