Signs and Symptoms

• Often none: pulsatile swelling in the popliteal fossa
• Acute ischaemia: pale, cold, pulseless, paraesthetic and paralysed limb - swelling in popliteal fossa – may be hard thrombosed) or pulsatile
• Sudden onset claudication

History and Examination

History:

• History of aneurysms elsewhere (e.g. aortic aneurysm) or family history
• Previous vascular symptoms (intermittent claudication)
• Vascular risk factors (smoking, hypertension, hypercholesterolaemia)

Examination:

• Palpate popliteal pulse – behind and above the knee: easily palpable, big pulse may indicate an aneurysm
• Examine other leg – often bilateral
• Pulse assessment and Doppler signal examination
• If acute ischaemia Urgent assessment of viability (paraesthesia/paralysis/muscle tenderness)

Differential Diagnoses

• Embolus -Is patient in AF?
• Acute thrombosis in chronic atherosclerosis

• 6 P's of acute ischaemia
  • Pale
  • Painful
  • Perishing with cold
  • Pallor
  • Paralysis
  • Paraesthesia
• These should trigger emergency admission

• For acute thrombosis – nil required: emergency referral
• For asymptomatic but palpable aneurysms – outpatient duplex ultrasound examination may be requested – specify measurement of popliteal artery diameter
• Result can be discussed with vascular specialist by letter or email

• If limb is threatened – urgent vascular admission required
  • Consider bolus 5000iu heparin
  • Analgesia
  • Oxygen
  • IV fluids
• If non urgent – management of vascular risk factors including antiplatelet and statin therapy

Referral Criteria

• Acute thrombosis
• Asymptomatic but palpable aneurysms

Referral Instructions

For acute thrombosis

• immediate via ED or on call general surgical registrar

For asymptomatic but palpable aneurysms

• Refer via Radiology

For discussion with a consultant

• Ring switchboard and ask for vascular surgeon of the week.

Pathway Group

This guideline has been signed off on behalf of NHS Devon.

Publication date: May 2024