Important diagnostic features
Isolated arterial embolus
• Sudden-onset, severe ischaemia, no previous symptoms of
vascular disease, previous history of atrial fibrillation/recent
myocardial infarction, all peripheral pulses on the unaffected
limb normal (suggesting no underlying peripheral vascular disease
[PVD]).
• Limb usually acutely threatened due to complete occlusion
with no collateral supply.
• Common sites of impaction are: popliteal bi(tri)furcation, distal
superficial femoral artery (adductor canal), origin of the profunda
femoris. ‘Saddle’ embolus at aortic bifurcation causes
bilateral acute ischaemic limbs.
Trauma
• May be due to direct injury to the vessel or by secondary compression
due to bone fragments or haematoma.
• Direct injuries may be due to: complete division of the vessel,
distraction injury, damage and in situ thrombosis, foreign body,
false aneurysm.
Thrombosis (in situ)
• Usually associated with underlying atheroma predisposing to
thrombosis after minor trauma or immobility (after a fall or illness).
• May be subacute in onset, previous history of known vascular
disease or intermittent claudication, associated risk factors for
peripheral vascular disease, abnormal pulses in the unaffected
limb.
• Paradoxically, the limb may not be as acutely threatened as in
isolated arterial embolus since collateral vessels may already be
present due to underlying disease.
Graft thrombosis
Often subacute in onset, limb not acutely threatened, progressive
symptoms, loss of graft pulsation
Aneurysm thrombosis
• Commonest sitebpopliteal aneurysms.
• Sudden-onset limb ischaemia, acutely threatened, may be
associated embolization as well, non-pulsatile mass in popliteal
fossa, many have contralateral asymptomatic popliteal aneurysm.
