Peripheral Vascular Disease

Demographics: affects 10–15% of the population. Non-modifiable risk factors: increasing age, male sex, non-Caucasian race.

Most common symptom: intermittent claudication affecting the calf muscles — however, present in as few as 10% of patients; often asymptomatic.

History

Risk factors: smoking, diabetes, elevated blood pressure, dyslipidaemia, previous ulcers.

Red flags — the “6 Ps” of acute limb ischaemia: pulseless, perishingly cold, painful, paraesthesia, pallor (± paralysis). Acute limb ischaemia is a medical emergency, with an ~8 hour window before irreversible muscle/nerve damage risks a fasciotomy or amputation — call an ambulance for immediate transfer to a vascular surgical service; if transfer will be delayed, give heparin 5000 units SC/IV stat (not enoxaparin/clexane — unfractionated heparin is preferred pre-intervention since it’s more easily reversed if urgent surgery follows) while arranging transfer. Chronic limb ischaemia is often bilateral to some degree, so acute deterioration can present as “acute-on-chronic” — the same emergency threshold applies.

Acute arterial occlusion

Common causes: thrombosis superimposed on pre-existing atherosclerosis; thromboembolism from the heart, an aneurysm, or atheroma; thrombotic occlusion of an aneurysm; trauma. A medical emergency, presenting according to where the occlusion occurs — e.g. stroke, acute critical limb ischaemia, mesenteric artery occlusion. Anxiety and prostration + intense central pain + profuse vomiting ± bloody diarrhoea → think mesenteric arterial occlusion.

Chronic mesenteric ischaemia presents differently — a triad of post-prandial abdominal pain (“intestinal angina”), weight loss (from food avoidance), and loss of appetite, sometimes with steatorrhoea; PR bleeding is a late sign. Acute-on-chronic deterioration (sudden severe pain out of proportion to examination findings) is a surgical emergency.

Examination

General inspection for xanthoma. Blood pressure. Peripheral vascular exam: colour, warmth, skin appearance in the periphery, presence of ulcers, peripheral pulses, Buerger’s test. Cardiovascular exam: pulse, JVP, carotid artery bruit, heart sounds for evidence of valvular heart disease.

Investigations

Ankle-brachial index (ABI): < 0.9 mild, < 0.8 moderate, < 0.7 severe, < 0.5 critical. Measure ABI for atypical exertional leg pain post-exercise. Duplex ultrasound is non-invasive and defines sites of stenosis/occlusion — often the only imaging needed to plan endovascular intervention. Fasting lipid profile, fasting glucose, HbA1c.

Management

Manage cardiovascular risk — patients with intermittent claudication are at high cardiovascular risk.

Lifestyle modification:

• Smoking cessation — doubles 5-year survival, improves walking distance, reduces postoperative complications.
• Exercise — supervised programs consistently improve walking time/distance. Advise: walk until pain occurs, rest until it subsides, repeat to a total of 30 minutes, progressing to 60 minutes/day, 3–5 times/week.
• Diet: low salt, low fat, moderate added sugar; aim for a healthy weight.
• Foot care: consider podiatry referral to minimise tissue loss.

Pharmacotherapy:

• Antiplatelet: aspirin 100mg (clopidogrel is not PBS-listed for primary prevention).
• ACE inhibitors give a small increase in walking distance.
• High-intensity statin (atorvastatin or rosuvastatin, not simvastatin — PAD is an established-CVD indication) targeting LDL-C <1.4mmol/L and ≥50% reduction from baseline (2025 NHFA/CSANZ ACS guideline secondary-prevention target).

Refer to a vascular surgeon (for consideration of bypass grafting, endarterectomy, or endoluminal techniques) if: chronic limb ischaemia is present (rest pain, ischaemic ulceration, or gangrene); the diagnosis is uncertain; claudication limits work/lifestyle with no improvement after 4–6 months of exercise/risk-factor/medical management; or interventional management is felt appropriate by patient and GP.