Pseudoaneurysm Flashcards
What is a pseudoaneurysm?
- 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
Underlying causes of pseudoaneurysm
- Damage to vessel wall eg cardiac catherisation, repeated injections (eg IVDU), vasculitis, regional inflammation (eg splenic one in pancreatitis)
Most common location for pseudoaneurysm
- Femoral artery
- But can also occur at radial, carotid, abdominal or thoracic aorta
What happens if pseudoaneurysm become infected? How does this occur?
- More common in IVDU - unsterile needles
- –> septic and more likely to rupture
Aneurysm vs pseudoaneurysm
- Aneurysm - involves all 3 layers of arterial wall, more common males, smokers, increasing age
- Pseudoaneurysm - collection between media and adventitia, caused by direct trauma
Presentation of pseudoaneurysm
- Pulsatile lump
- Can be tender and painful
- Can be distal arterial occlusion due to compression –> limb ischaemia
Presentation of infected pseudoaneurysm
- Erythematous
- Tender
- Purulent material discharging from any sinus present
- Systemic features of sepsis - pyrexia, tachy etc
What happens if a patient reports the pseudoaneurysm has bled but now stopped?
- Needs close monitoring and urgent management
- May represent ‘herald bleed’
- = could rebleed at any time
herald = sign something is going to happen
Differentials for mass in arterial areas
- True aneurysms
- Haematoma - esp after procedure/trauma
- Abscess - esp in IVDU
Imaging for pseudoaneurysm
- Assess distal pulse status - PRIOR to intervention
- Duplex USS - turbulent forward and backward flow (‘yin-yang sign’)
- CT - if difficult with USS
Bloodsand bedside tests for pseudoaneurysm
- 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
Management of small pseudoaneurysms
- Can be left alone
Management of larger or symptomatic pseudoaneurysm
- USS guided compression
- OR USS guided thrombin injection
What is USS guided compression?
- Can be painful to do
- Requires 30 minutes of direct pressure at neck of aneurysm
USS guided thrombin injection into pseudoaneurysm
- 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
When is endovascular stenting used?
- 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
How is surgical repair or ligation of pseudoaneurysm done?
- 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
Management of infected pseudoaneurysm - initial
- Risk of perforation high
- Pressure dressing (if purlent discharge) and urgent imaging
Definitive management infected pseudoaneurysm
- 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
What usually happens following ligation of infected pseudoaneurysm
- Collateral supply can often provide distal blood flow
- If femoral involvement though some cases then will eventually need amputation
