Limb ischaemia can be divided into an acute and a chronic form. The diagnosis of acute ischaemia must be made promptly; immediate revascularisation is necessary in most cases. Chronic critical limb ischaemia is the most severe form of peripheral arterial occlusive disease (PAOD). It is characterised by rest pain or by necrosis or gangrene.
Acute limb ischaemia (“acute limb ischaemia”, ALI) represents an acutely occurring hypoperfusion of the limb that is no older than 2 weeks. The causes are usually embolisation or local thrombosis on the basis of a pre-existing pathology such as PAOD.
Chronic limb ischaemia (“chronic limb ischaemia”, CLI) refers to rest pain or ischaemic skin lesions such as ulcers or gangrene (Fontaine stage III and IV or Rutherford categories 4–6). It has a high association with cerebrovascular and cardiovascular events. Chronicity is spoken of when symptoms persist for more than 2 weeks.
TASC II Criteria
The consensus document TASC II (Transatlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease) addresses aspects of revascularisation in PAOD [1]. According to the TASC criteria, therapeutic treatment options can be derived depending on the length of the local occlusion/stenosis. The length of the stenosis and its localisation regions determine the therapy: endovascular or open vascular surgery.