Arterial Aneurysms

Question 1

Aneurysms are a dilatation of ALL layers of the vessel by >50%. The most common place for an aneurysm is the aorta but they can occur elsewhere (popliteal).

What are key features of abdominal aortic aneurysms?

Answer 1

• Occur primarily as a result of failure of elastic proteins within EC matrix
• After age of 50yrs, normal diameter of infrarenal aorta is 1.5cm (F) and 1.7cm (M)
• Diameters of 3+ cm considered aneurysmal
• > 90% aneurysms originate below renal arteries

Question 2

What are risk factors for aneurysms?

Answer 2

• Cigarette smoking
• FHx
• Increased age
• Male sex (prevalence)
• Female sex (rupture)
• Congenital/connective tissue disorders (eg. Marfan’s)

Question 3

Screening for an abdominal aortic aneurysm consists of a single abdominal ultrasound for males aged 65.

What are the thresholds for screening outcomes?

Answer 3

Question 4

What are clinical features of AAA?

Answer 4

• Asymptomatic until rupture
• Rupture leads to triad of:
  
  • Abdominal +/- back pain
  • Pulsatile abdominal mass
  • Hypotension

Important to ask about RFs eg. smoking

Question 5

Which investigations are done for AAA?

Answer 5

• FAST scan → US by bedside; v high sensitivity and specificity
• FBC / ESR / CRP / Crossmatch
• CT Angio → demonstrate retroperitoneal haematoma, discontinuity of aortic wall or extravasation of contrast into peritoneal cavity which are all signs of rupture

Question 6

What is the management for a ruptured AAA?

Answer 6

• ABCDE
• Open repair vs EVAR
• EVAR causes lower mortality during surgery but eventually morbidity catches up with open repair

Question 7

What is a key complication of EVAR?

Answer 7

• Endo-leak
• Stent fails to exclude blood from aneurysm + usually presents without symptoms on routine follow up
• Type 1a → proximal
• Type 1b → distal
• Type 2 → from artery
• Type 3 → from stent

Question 8

If one aneurysm is found, the rest of the peripheral vascular system should be carefully examined.

What are features of popliteal aneurysm?

Answer 8

• 2^nd most common
• Often bilateral
• May cause distant emboli or may thrombose → acutely ischaemic limb
• If asymptomatic but >3cm → repair w/ bypass graft

Question 9

What are key features of thoracic aortic aneurysms?

Answer 9

• May be of aortic arch or ascending/descending thoracic aorta
• Sx → chest pain / back pain / aorto-oesophageal fistula / SVC obstruction / recurrent laryngeal nerve + tracheal compression

Question 10

How might femoral aneurysms present?

Answer 10

Groin swelling