Pseudoaneurysm

Question 1

What is a pseudoaneurysm?

Answer 1

• False aneurysm
• Breach in arterial wall
• = accumulation of blood between tunica media (inside) and adventitia (outside)
• Direct connection between vessel lumen and aneurysm lumen so can continue to increase in size
• If left, they often continue to grow and if not treated –> perforate

Question 2

Underlying causes of pseudoaneurysm

Answer 2

• Damage to vessel wall eg cardiac catherisation, repeated injections (eg IVDU), vasculitis, regional inflammation (eg splenic one in pancreatitis)

Question 3

Most common location for pseudoaneurysm

Answer 3

• Femoral artery
• But can also occur at radial, carotid, abdominal or thoracic aorta

Question 4

What happens if pseudoaneurysm become infected? How does this occur?

Answer 4

• More common in IVDU - unsterile needles
• –> septic and more likely to rupture

Question 5

Aneurysm vs pseudoaneurysm

Answer 5

• Aneurysm - involves all 3 layers of arterial wall, more common males, smokers, increasing age
• Pseudoaneurysm - collection between media and adventitia, caused by direct trauma

Question 6

Presentation of pseudoaneurysm

Answer 6

• Pulsatile lump
• Can be tender and painful
• Can be distal arterial occlusion due to compression –> limb ischaemia

Question 7

Presentation of infected pseudoaneurysm

Answer 7

• Erythematous
• Tender
• Purulent material discharging from any sinus present
• Systemic features of sepsis - pyrexia, tachy etc

Question 8

What happens if a patient reports the pseudoaneurysm has bled but now stopped?

Answer 8

• Needs close monitoring and urgent management
• May represent ‘herald bleed’
• = could rebleed at any time

herald = sign something is going to happen

Question 9

Differentials for mass in arterial areas

Answer 9

• True aneurysms
• Haematoma - esp after procedure/trauma
• Abscess - esp in IVDU

Question 10

Imaging for pseudoaneurysm

Answer 10

• Assess distal pulse status - PRIOR to intervention
• Duplex USS - turbulent forward and backward flow (‘yin-yang sign’)
• CT - if difficult with USS

Question 11

Bloodsand bedside tests for pseudoaneurysm

Answer 11

• Routine bloods - FBC, U&E, clotting, CRP
• Blood cultures
• Pus swab MC&S if discharging
• Ensure blood units are cross matched in case of rupture

Question 12

Management of small pseudoaneurysms

Answer 12

• Can be left alone

Question 13

Management of larger or symptomatic pseudoaneurysm

Answer 13

• USS guided compression
• OR USS guided thrombin injection

Question 14

What is USS guided compression?

Answer 14

• Can be painful to do
• Requires 30 minutes of direct pressure at neck of aneurysm

Question 15

USS guided thrombin injection into pseudoaneurysm

Answer 15

• Into lumen of pseudoaneurysm
• Under US guidance
• Forms a thrombus within pseudoaneurysm then closes it off
• Highest success if have long and narrow neck
• f/u imaging to ensure resolved

Question 16

When is endovascular stenting used?

Answer 16

• Depends on patient and location of aneurysm
• Endovascular often not possible due to location and then have insufficient space to land stent without covering a major branch
• They can also leak

Question 17

How is surgical repair or ligation of pseudoaneurysm done?

Answer 17

• Can clamp each end of artery with pseudoaneurysm
• Then open it and repair directly or using vein/bovine patch
• Occasionally you need ligation - but sometimes this can cause distal ischaemia and a bypass may need to be used

Question 18

Management of infected pseudoaneurysm - initial

Answer 18

• Risk of perforation high
• Pressure dressing (if purlent discharge) and urgent imaging

Question 19

Definitive management infected pseudoaneurysm

Answer 19

• Surgical ligation
• Occasionally will need bypass graft - using vein/bovine is preferred as they are more resistant to infection
• Tunelling graft through non-infected area is recommended

Question 20

What usually happens following ligation of infected pseudoaneurysm

Answer 20

• Collateral supply can often provide distal blood flow
• If femoral involvement though some cases then will eventually need amputation