Peripheral Arterial Disease (PAD) ✅

🩸 Peripheral Arterial Disease (PAD) (often called “PVD”) is systemic atherosclerosis affecting limb arteries, most commonly the legs. It is a powerful marker of coronary and cerebrovascular disease—many patients with PAD are more likely to die from MI or stroke than from limb loss. Red flags: rest pain, tissue loss (ulcer/gangrene), acute limb ischaemia (the “6 Ps”).

ℹ️ About

• 🦵 Legs are most commonly affected; PAD frequently coexists with carotid and coronary disease.
• 📈 Often under-recognised: patients may be asymptomatic yet still have high cardiovascular risk.
• ⚠️ Rest pain or ulcer/gangrene = urgent vascular assessment (critical/chronic limb-threatening ischaemia, CLTI).

🧬 Pathophysiology

• 🧱 Atherosclerosis: lipid + inflammatory plaque at arterial bifurcations → luminal narrowing.
• 🩸 Reduced perfusion → intermittent claudication on exertion.
• 💥 Plaque rupture → thrombosis → acute limb ischaemia.
• 🔁 Collaterals develop but often inadequate in advanced disease.
• 🩺 Diabetes/CKD → medial calcification → incompressible arteries; ABPI may be falsely high (toe pressures/duplex better).

🚬 Risk Factors

• 🚬 Smoking (most important modifiable).
• 🍩 Diabetes mellitus (distal disease, ulcer risk).
• 🍔 Dyslipidaemia, 💓 hypertension, ⚖️ obesity/inactivity, metabolic syndrome.
• 👴 Age, male sex, family history of premature vascular disease.
• 🧑‍⚕️ CKD, sedentary lifestyle, poor diet.
• 🩸 Buerger’s disease (young smokers, thrombotic inflammatory disease).

🧑‍⚕️ Clinical Features

• 🚶 Intermittent claudication: reproducible exertional pain, relieved by rest.
• 🌙 Rest pain: severe foot/toe pain, worse at night, relieved by dangling limb.
• 🩹 Tissue loss: ulcers, gangrene, poor healing.
• 🦵 Signs: cool limb, shiny/atrophic skin, hair loss, thickened nails, slow cap refill, bruits, reduced pulses.
• 👨‍🦽 Leriche syndrome: aorto-iliac disease → buttock/thigh claudication ± impotence.
• 🧠 Check for systemic risk: carotid disease, TIA/stroke history.

📍 Claudication Localisation

• 🍑 Buttock/hip → aorto-iliac
• 🦵 Thigh → common femoral / aorto-iliac
• 👟 Upper 2/3 calf → superficial femoral
• 🧦 Lower 1/3 calf → popliteal
• 🦶 Foot → tibial/peroneal (diabetic distal disease)

❓ History

• ⏱️ Onset, progression, stability of symptoms.
• 🚶 Claudication distance, speed, gradient.
• 📍 Pain location, relieving factors (rest vs dependency).
• 🩸 Cardiovascular history: angina, MI, TIA/stroke, AF, heart failure.
• 💊 Medications, adherence, smoking/alcohol, infection signs.

🔍 Examination

• 👀 Inspect: colour, trophic changes, ulcers, infection, gangrene.
• ✋ Palpate pulses: femoral → popliteal → posterior tibial → dorsalis pedis.
• 👂 Auscultate bruits over femoral/iliac regions.
• 🦵 Buerger’s test: elevation pallor, dependency rubor.

📈 Severity Spectrum

🧠 Limb ischaemia = supply–demand mismatch. Symptoms progress: exertional pain → rest pain/tissue loss → sudden threatened limb.

• 🚶 Intermittent claudication: pain only on exertion; relieved by rest.
• 🦶🔥 Critical limb ischaemia / CLTI: rest pain and/or tissue loss; urgent vascular referral.
• ⚡ Acute limb ischaemia (ALI): sudden onset; “6 Ps” = Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Poikilothermia.

🔬 Investigations

• 🧪 Bloods: FBC, U&E, LFTs, lipids, HbA1c, CRP if infected.
• 📈 ECG ± echo for cardiac source.
• 🩺 ABPI: <1.0 abnormal, <0.9 PAD likely, <0.5 severe; >1.4 → toe pressures/duplex.
• 📊 Duplex Doppler: maps stenoses and flow.
• 🖼️ CTA/MRA: pre-intervention planning.
• 🩻 Catheter angiography: for complex lesions/endovascular planning.

💊 Management

• 🚭 Smoking cessation.
• 🏃 Supervised exercise therapy.
• 🦶 Foot care and podiatry for ulcer prevention.
• 💊 Antiplatelets (aspirin/clopidogrel) for CV protection.
• 💊 High-intensity statin + aggressive risk factor management (BP, diabetes, weight).
• 💊 ACEi/ARB where indicated; manage AF/embolic risk.
• 🔧 Endovascular: angioplasty ± stent for suitable lesions.
• 🔨 Surgical bypass or endarterectomy for extensive disease.
• 🦿 Amputation only if limb non-viable, infection uncontrolled, or failed revascularisation.

🚩 Red Flags

• 🌙 Rest pain (especially nocturnal, requiring dangling limb).
• 🩹 Non-healing ulcer, spreading infection, or gangrene.
• ⚡ Sudden severe pain + cold/pale limb + neuro deficit (ALI).
• 📉 Rapid decline in walking distance or new tissue loss.

🧪 Cases

• Case 1 - Intermittent Claudication: 66yo smoker, calf pain after 200 m, relieved by rest; cool legs, weak DP pulses. Plan: ABPI/duplex, exercise, smoking cessation, antiplatelet + statin, optimise BP/DM.
• Case 2 - CLTI: 74yo with nocturnal foot rest pain, dusky toes, non-healing ulcer. Plan: urgent vascular referral, analgesia, antibiotics if infected, imaging for revascularisation (angioplasty/bypass).
• Case 3 - ALI: 62yo with AF, sudden cold/pale leg with sensory/motor loss. Plan: emergency pathway, IV heparin, urgent embolectomy/thrombectomy.

📖 References

• NICE CG147 – Peripheral arterial disease: diagnosis and management
• NICE CKS – Peripheral arterial disease
• NICE CKS – Intermittent claudication