Peripheral vascular disease

Overview

Peripheral arterial disease (PAD) - narrowing of lower limb arteries, almost always from atherosclerosis. A marker of systemic cardiovascular disease with elevated MI and stroke risk.

Risk factors

Key risk factors
Smoking - most impactful modifiable risk factor
Diabetes mellitus
Hypertension
Dyslipidaemia
Age >50 (steeper rise after 70)
Atrial fibrillation (embolic ALI)

Presentation

•Intermittent claudication - reproducible cramping pain in calf (femoro-popliteal) or thigh/buttock (aorto-iliac), on walking, relieved by 1-5 min rest

•Rest pain - burning forefoot/toe pain, worse at night and on elevation; relieved by hanging leg dependently

•Skin/trophic changes - dependent rubor, elevation pallor, dry/shiny skin, hair loss on dorsum, thickened nails

•Ischaemic ulcers - over pressure points (heel, toe tips); gangrene starts distally

•Reduced/absent pulses - femoral, popliteal, posterior tibial, dorsalis pedis; document bilaterally

•Bruits - femoral, aortic, carotid

•Acute limb ischaemia (ALI) - 6 Ps: Pain, Pallor, Pulselessness, Perishing cold, Paraesthesia, Paralysis

🚨
Paraesthesia and paralysis in ALI indicate threatened neuromuscular viability - this is a vascular surgical emergency requiring immediate referral.

Investigations

🥇 First-line

•ABPI - ≤0.9 indicates PAD; <0.5 indicates critical ischaemia; >1.3 suggests non-compressible (calcified) vessels (common in diabetes)

•ECG - screen for AF (embolic source in ALI) and ischaemic heart disease

•Bloods - FBC, fasting glucose/HbA1c, lipid profile, U&E, coagulation if ALI suspected

•Duplex ultrasound - first-line imaging; identifies site and degree of stenosis before revascularisation planning

•CT angiography - detailed pre-operative vascular mapping

•MR angiography - preferred in renal impairment (avoids nephrotoxic contrast and ionising radiation)

🏆 Gold standard

•Digital subtraction angiography (DSA) - invasive, highest resolution; allows simultaneous intervention (angioplasty/stenting)

Differential diagnosis

Key differentials from intermittent claudication
DiagnosisKey distinguishing featuresABPI
Spinal stenosis (neurogenic claudication)Pain radiates from back into both legs; relieved by sitting/flexing forward, not just stoppingNormal
Venous claudicationBursting/aching after exercise; history of DVTNormal
Musculoskeletal (OA)Pain related to joint movement pattern, not purely exercise distanceNormal
Chronic compartment syndromeYounger athletes; resolves slowly after restNormal

Diagnosis	Key distinguishing features	ABPI
Spinal stenosis (neurogenic claudication)	Pain radiates from back into both legs; relieved by sitting/flexing forward, not just stopping	Normal
Venous claudication	Bursting/aching after exercise; history of DVT	Normal
Musculoskeletal (OA)	Pain related to joint movement pattern, not purely exercise distance	Normal
Chronic compartment syndrome	Younger athletes; resolves slowly after rest	Normal

Management

•First-line (all patients):

•Smoking cessation - single most effective intervention; slows progression, reduces cardiovascular mortality

•Supervised exercise programme - structured walking ≥3 months; NICE first-line for intermittent claudication

•Antiplatelet: clopidogrel 75 mg OD preferred (NICE CG147); aspirin 75 mg OD is alternative

•High-intensity statin: atorvastatin 80 mg OD

•Treat hypertension (target <140/90 mmHg), optimise glycaemic control

🥈 Second-line

•Endovascular revascularisation (angioplasty ± stenting) - for disabling claudication or CLTI not responding to conservative measures

•Surgical bypass grafting - complex/long-segment disease not amenable to angioplasty

🥉 Third-line

•Amputation - when revascularisation not possible or limb not salvageable

•Naftidrofuryl oxalate (vasodilator) - modest evidence for improving walking distance; offered if supervised exercise declined or unsuitable

•Acute limb ischaemia: Immediate vascular surgery referral + anticoagulate with unfractionated heparin; options include catheter-directed thrombolysis, surgical embolectomy, or bypass

💡
PAD is a coronary artery disease equivalent - annual mortality is driven mainly by MI and stroke, not limb loss. All patients need aggressive cardiovascular risk factor modification.

Complications

•Progression to critical limb-threatening ischaemia (CLTI) and gangrene

•Major amputation - ~25% of CLTI patients within 1 year without revascularisation

•MI and stroke - 2-3 fold increased risk due to systemic atherosclerosis

•Reperfusion injury after revascularisation - hyperkalaemia, acute kidney injury from ischaemic muscle

Prognosis

•Intermittent claudication - 70-80% stable or improve with conservative management

•CLTI - 1-year mortality approaches 20-25% even with intervention