Acute and chronic ischaemia of the limb

Limb ischaemia is an important clinical problem due to the high prevalence of atherosclerosis in the UK population. The main risk factors for limb ischaemia are smoking and diabetes mellitus. In young patients, alternative diagnoses of emboli and thrombosis, arteritis, congenital anomalies, fibrosis and traumatic arterial injury must be considered. Intermittent claudication, critical limb ischaemia and the acute or ‘threatened’ limb are clinical diagnoses. Non-invasive arterial assessment by colour duplex, MRI and CT have an increasing role alongside angiography in confirming the diagnosis and planning intervention. Patients with intermittent claudication require aggressive modification of risk factors, interventions to stop smoking, an anti-platelet agent, a statin, and structured exercise classes. In patients who are severely incapacitated or who have aortoiliac disease, intervention (usually by percutaneous angioplasty) is considered. Patients with critical limb ischaemia require intervention if limb loss is to be avoided; arterial reconstruction is preferable to primary amputation as preserving mobility is an important determinant of quality of life. The acue ‘threatened’ limb is a surgical emergency and requires immediate intervention, best performed in a specialized unit.