Write a short note on peripheral vascular disease, including Raynaud's phenomenon.

Peripheral Arterial Disease — Definition

Peripheral arterial disease (PAD) is obstruction of arterial blood supply to the limbs, most often from atherosclerosis of the lower limb arteries. It is both a cause of limb morbidity and, more importantly, a marker of generalised atherosclerosis — patients with PAD have a markedly increased risk of myocardial infarction and stroke, and most die of cardiovascular causes rather than of limb disease.

Causes of Obstructive Peripheral Vascular Disease

Clinical Features of Chronic Pad

• INTERMITTENT CLAUDICATION — cramping muscular pain precipitated by walking a reproducible distance and relieved within minutes by rest. The site indicates the level of disease: calf claudication → superficial femoral artery; thigh → common femoral or external iliac; buttock → aorto-iliac.
• LERICHE SYNDROME — aorto-iliac occlusion causing the triad of buttock and thigh claudication, absent femoral pulses, and erectile dysfunction.
• CRITICAL LIMB ISCHAEMIA — rest pain (typically nocturnal, in the forefoot, relieved by hanging the leg over the edge of the bed), ulceration and gangrene; indicates a threatened limb.
• Signs: absent or diminished pulses, cool pale limb, hair loss, shiny atrophic skin, thickened nails, prolonged capillary refill, arterial ulcers (painful, punched-out, on the toes, heel and lateral malleolus), Buerger's test (elevation pallor with dependent rubor), and reduced venous filling.

Fontaine classification: I — asymptomatic; II — intermittent claudication; III — rest pain; IV — ulceration or gangrene.

Arterial versus venous ulcers — a standard comparison:

Thromboangiitis Obliterans (buerger's Disease)

A non-atherosclerotic, segmental, inflammatory occlusive disease of small and medium arteries and veins of the limbs, with a strong and essentially obligatory association with TOBACCO USE. It typically affects young men (under 45), and is notably common in India, the Middle East and South-East Asia — where heavy smoking and bidi use begin early.

Features:

• distal ischaemia of the hands and feet with claudication of the foot arch and calf, rest pain, digital ulceration and gangrene
• migratory superficial thrombophlebitis (a highly characteristic feature)
• Raynaud's phenomenon
• normal proximal pulses with absent distal pulses. Angiography shows segmental occlusions with "corkscrew" collaterals and normal proximal vessels.

Management: ABSOLUTE AND COMPLETE CESSATION OF ALL TOBACCO — this is the only effective treatment, and continued smoking (even a few cigarettes, or smokeless tobacco) leads inexorably to amputation. Supportive care with wound management, analgesia, iloprost for critical ischaemia, and sympathectomy or bypass in selected patients — but no intervention substitutes for stopping tobacco.

Raynaud's Phenomenon

Definition: episodic, reversible vasospasm of the digital arteries and arterioles, provoked by cold or emotional stress, producing the classic TRIPHASIC COLOUR CHANGE:

1. WHITE (pallor) — vasospasm and ischaemia

2. BLUE (cyanosis) — deoxygenation of static blood

3. RED (rubor) — reactive hyperaemia on rewarming, often with burning pain and tingling

Causes of secondary Raynaud's:

• Connective tissue disease — SYSTEMIC SCLEROSIS (the commonest and most important; Raynaud's is often the first symptom, preceding other features by years), SLE, mixed connective tissue disease, dermatomyositis, rheumatoid arthritis, Sjögren's syndrome
• Occupational — VIBRATION WHITE FINGER from prolonged use of vibrating tools; cold exposure
• Obstructive arterial disease — atherosclerosis, Buerger's disease, thoracic outlet syndrome, cervical rib
• Drugs — beta-blockers, ergotamine, methysergide, cisplatin, bleomycin, ciclosporin, sympathomimetics
• Haematological — cryoglobulinaemia, cold agglutinin disease, polycythaemia, paraproteinaemia
• Others — hypothyroidism, hepatitis B and C, malignancy

Investigations

• Ankle-brachial pressure index (ABPI) — the key bedside test for PAD: normal 0.9–1.3; claudication 0.4–0.9; critical ischaemia < 0.4. Beware falsely HIGH or normal values (> 1.3) in DIABETICS and CKD from medial arterial calcification, which makes the vessels incompressible — use toe-brachial index or Doppler waveform analysis instead.
• Duplex ultrasound — first-line imaging; CT or MR angiography for planning intervention; catheter angiography where intervention is intended.
• Exercise treadmill testing with post-exercise ABPI where the diagnosis is uncertain.
• For Raynaud's: nailfold capillaroscopy (the key discriminator), ANA and extractable nuclear antigens, ESR, CBC, thyroid function, cryoglobulins, and hepatitis serology.
• Cardiovascular risk assessment for all — lipids, glucose and HbA1c, renal function, ECG.

Management

Peripheral arterial disease:

1. RISK FACTOR MODIFICATION — the priority, because these patients die of heart attacks and strokes, not of their legs: smoking cessation (the single most important intervention), statin therapy for all, antiplatelet therapy, blood pressure and diabetes control.

2. SUPERVISED EXERCISE PROGRAMME — the most effective treatment for claudication, improving walking distance as much as revascularisation in many patients by promoting collateral development. Consistently under-prescribed.

3. Cilostazol for symptomatic claudication (contraindicated in heart failure).

4. Foot care — daily inspection, appropriate footwear, prompt treatment of injury and infection; podiatry, particularly in diabetics.

5. REVASCULARISATION — angioplasty with or without stenting, or surgical bypass — for critical limb ischaemia, disabling claudication refractory to conservative treatment, and tissue loss.

6. Amputation — for irreversible gangrene, uncontrolled infection or intractable pain.

Raynaud's phenomenon:

• Keep the whole body warm, not just the hands — gloves, layers, hand warmers; avoid sudden cold exposure.
• STOP SMOKING — absolutely essential; avoid beta-blockers and other precipitating drugs.
• Calcium channel blockers (nifedipine, amlodipine) — first-line drug treatment.
• Phosphodiesterase-5 inhibitors (sildenafil); topical nitrates; ARBs and SSRIs as alternatives.
• Severe or ulcerating disease: intravenous iloprost, bosentan (which prevents new digital ulcers in systemic sclerosis), digital sympathectomy, botulinum toxin injection.
• Treat the underlying disease in secondary Raynaud's, and monitor for evolving connective tissue disease.