Definition
- Atherosclerosis of the peripheral arteries
- 65% have coexisting clinically relevant cerebral or coronary artery disease.
- Cardiovascular risk factors should be identified and treated aggressively.
- The most important presentation is intermittent claudication
Disease pattern
- Intermittent claudication.
- Critical limb ischaemia
- Acute limb threatening ischaemia (See next section)
Symptoms
- Cramping pain in the calf, thigh, or buttock after walking for a given distance (the claudication distance) and relieved by rest
- calf claudication = femoral disease
- buttock claudication = iliac disease).
- Ulceration, gangrene and foot pain at rest—eg burning pain at night relieved by hanging legs over side of bed—are the cardinal features of critical ischaemia
- Buttock claudication ± impotence imply Leriche’s syndrome
- Young, heavy smokers are at risk from Buerger’s disease (thromboangiitis obliterans)
Signs
- Absent femoral, popliteal, or foot pulses
- cold, white leg(s)
- Atrophic skin
- punched out ulcers (often painful)
- postural/dependent colour change
- Buerger’s angle (angle that leg goes pale when raised off the couch) of <20° and capillary filling time >15s are found in severe ischaemia.
Investigations
- Exclude DM
- Arteritis (esr/crp)
- FBC (anaemia, polycythaemia)
- U&E (renal disease)
- Lipids (dyslipidaemia)
- Thrombophilia screen and serum homocysteine if <50 years.
Ankle-Brachial Pressure Index (ABPI)
- Normal = 1–1.2
- PAD= 0.5–0.9
- Critical limb ischaemia <0.5 or ankle systolic pressure <50mmHg
- Acute limb threatening ischaemia <0.3
Beware falsely high results from incompressible calcified vessels in severe atherosclerosis e.g. DM
Imaging
- 1st line: Colour duplex US
- If intervention considered: MR/CT angiography for extent and location of stenoses and quality of distal vessels (‘run-off’).
Management
Conservative
- Cardiovascular risk factor modification: hypertension, diabetes, obesity, smoking etc.
- Supervised exercise (to the point of maximal pain) for 2hr/wk for 3 months
- Antiplatelet agent: 1 line) Clopidogrel 75mg; 2 line) Aspirin 75mg
- Risk factor modification:Quit smoking (vital). Treat hypertension and high cholesterol. Prescribe an antiplatelet agent (unless contraindicated), to prevent progression and to reduce cardiovascular risk. Clopidogrel is recommended as 1st-line.
- Vasoactive drugs, eg naftidrofuryl oxalate, in those who do not wish to undergo revascularization and if exercise fails to improve symptoms.
Surgical
- 1st line: Percutaneous transluminal angioplasty (PTA): is used for disease limited to a single arterial segment
- 2nd line:Bypass surgery: If extensive disease but distal run-off is good (i.e. distal arteries filled by collateral vessels). Procedures include femoral-popliteal bypass, femoral-femoral crossover, and aorto-bifemoral bypass grafts. Autologous graft > prosthetic grafts.
- 3rd line: Amputation: in intractable pain, sepsis, gangrene, and failed alternative strategies. Decision by the patient and vascular multidisciplinary team