Abdominal aortic aneurysm

Question 1

What is an AAA

Answer 1

Aortic dilation >50% original diameter (>3cm)

Permanent + irreversible

Question 2

How common is it

Answer 2

3% those over 50

Question 3

Who gets it

Answer 3

M>F (3:1)

Elderly

Question 4

What causes it

Answer 4

Degeneration of elastic lamellae + smooth muscle loss

• trauma
• infection
• Inflammatory disease
• Connective tissue disorder - Marfans, ehlers-danlos

Question 5

What are the risk factors

Answer 5

• increased age
• smoking
• FHx
• hyperlipidaemia
• male
• COPD

Question 6

What are the risk factors for rupture

Answer 6

• Wide diameter >5.5cm
• HTN
• Smoking
• Female
• FH

Question 7

What is the pathophysiology of AAA

Answer 7

• Most commonly infra-renal
• Most AAAs = fusiform aneurysm
• TRUE aneurysm = dilation involving all layers
• PSEUDOANEURYSM = blood collection in out layer (adventitia) only

Question 8

What are the symptoms

Answer 8

UNRUPTURED

• Asymptomatic
• May Px w. abdo, back, loin, groin pain

RUPTURE - emergency

• Sudden onset
• intermittent/continuous abdo pain
• Radiates to groin/iliac fossa/ back
• Syncope
• Collapse

Question 9

What are the signs

Answer 9

• Hypovolaemic shock

- Expansile abdo mass

Question 10

What are the DDx

Answer 10

• GI bleed
• Renal colic
• Ischaemic bowel
• Appendicitis
• Gallstones
• Diverticulitis
• LBO

Question 11

What are some investigations

Answer 11

• BLOODS - FBC, U+E, clotting, LFT, cross-match, CRP

- IMAGING –> CXR/AXR, USS, CT, MRI angiography

Question 12

How do you treat and AAA

Answer 12

SMALL DIAMETER/ UNRUPTURED

• USS monitoring
• Stop smoking
• Statins
• Antiplatelets

SURGERY - if >5.5cm or ruptures

• Open repair
• Stenting (EVAR) –> less mortality but higher graft complications