Limb Ischaemia and Peripheral Vascular Disease Flashcards
What is peripheral vascular disease
- This is a commonly caused by atherosclerosis and usually affects the aorto-illac or infra-inguinal arteries
What are the two types of limb ischaemia
- Chronic lower limb ischaemia
- Acute lower limb ischaemia
What are the risk factors for chronic lower limb ischaemia
- smoking
- diabetes
- hypercholesterolaemia
- hypertension
What classification is used to describe peripheral arterial disease
Fontamine classification
What are the symptoms according to the Fontaine classification for peripheral arterial disease
- Stage 1 - asymptomatic
- Stage 2 - intermittent claudication
- Stage 3 - rest pain/nocturnal pain
- Stage 4 - necrosis/gangrene
What is intermittent claudication
- this is when patients complain of exertion discomfort most commonly in the calf which is relieved by rest
Where do patients with aorta-iliac disease feel pain
- in the buttock
What is rest pain
- patients with rest pain experience severe, unremitting pain in the foot which stops a patient from sleeping
- partially relieved by dangling the foot over the edge of the bed or standing on a cold floor
What are the signs of chronic limb ischaemia
- cold
- dry skin
- lack of hair
- pulses diminish or absent
- ulceration may occur
- dark discolouration of the toes
- gangrene
- abdomen should be examined for a possible anuesym
What are the differential diagnosis for chronic limb ischaemia
- spinal canal claudication
- osteoarthritis hip/knee
- peripheral neuropathy (associated with numbness and tingling)
- popliteal artery entrapment (young patients who may have normal pulses)
- venous claudication (bursting pain on walking with a previous history of DVT)
- Fibromuscular dysplasia
- Buerger’s disease (young males, heavy smokers)
What investigations do you carry out for someone with limb ischaemia
- severity of the disease is indicated by the ankle/brachial pressure index
- Digital subtraction angiography
- duplex ultrasound using B mode ultrasound and colour doppler
- three dimensional contrast enhanced MR angiography
- CT angiography
What is an ankle/brachial pressure index
- measurement of the cuff pressure at which blood flow is detectable by the brachial artery (ankle/brachial pressure)
What level is the ankle/brachial pressure index at with intermittent claudication
- it is associated with an ABPI of 0.5-0.9
- values of greater than 0.5 are associated with critical limb ischaemia
What lifestyle management should be recommended with patients with chronic limb ischaemia
- stop smoking
- diabetes - improve car e
- hypercholesterolaemia should be treated with statins
- Prescribe antiplatente agents - clopidogrel = 1st line
What is the pharmacological therapy used to treat chronic limb ischaemia
- Cilostazol
- naftidrofuryl
What does Cilostazol do
- this is a phosphodiesterase III inhibitor that increases level of cAMP, this produces vasodilation and reversibly inhibits platelet aggregation
What does naftidrofuryl do
- is a vasodilator agent that inhibits vascular and platelet 5-hydroxytryptamine receptors and can reduce lactic acid levels
What is the surgical treatment for chronic limb ischaemia
- percutaneous transluminal angioplasty
- bypass procedures
- Amputation
What are the symptoms of acute lower limb ischaemia
- pain
- pallor
- paraesthesia
- paralysis
- perishingly cold
What are the signs of acute lower limb ischaemia
- limb is cold
- mottling and marbling of the skin
- sensation and movement of the leg are reduced in severe ischaemia
- compartment syndrome can develop
What are the common causes of acute lower limb ischaemia
- embolic disease - due to cardiac thrombus and cardiac arrhythmias
- thrombotic disease - usually due to chronic atherosclerotic stenosis in a patient who has previously reported symptoms of claudication
- Trauma - causing compartment syndrome
What is the medical management of acute lower limb ischaemia
It is dependent on the degree of ischaemia
- patients showing improvement may be treatable with heparin and appropriate treatment of the underlying cause
What is the surgical and radiological management of acute lower limb ischaemia
- patients with mild to moderate ischaemic symptoms who have an occluded graft may need graft thrombolysis
- Intra arterial thrombolysis may reveal an underlying stenosis within a graft or native vessel that can be treated with angioplasty
- patients with embolus will have it removed
- bypass graft
What happens when an ischaemic limb is revascuarlized
- can cause a repercussion injury, with the release of toxic metabolites into circulation
- this can lead to compartment syndrome which will require a fasciotomy
What investigations should be carried out on emergency acute limb ischaemia
- Routine bloods including a serum lactate
- A thrombophilia screen
- ECG
- Doppler ultrasound
- CT angiography
What are the cardinal features of critical ischaemia
- ulceration and gangrene
- foot pain at rest - relieve at night by handing legs off bed
What are the signs of limb ischaemia
- absent femoral, popliteal or foot pulses
- cold white legs
- atrophic skin
- punched out ulcers (often painful)
- postural dependent colour change
Severe ischaemia
- capillary refill greater than 15 seconds
- Buerger’s Angle ( angle that leg goes pale when raised of the couch) less than 20 degrees
How do you manage claudication
- Supervised exercise programme (2h/week of 3 months) - reduce symptoms by improving collateral blood flow; exercise to the point of maximal pain
- Vasoactive drugs - e.g. Naftidrofuryl oxalate - modest benefit
Describe how percutaneous transluminal angioplasty work
- Used for disease limited to a single arterial segment
- Balloon is inflated in narrowed segment
- Stents can be used to maintain arterial patency
How does surgical reconstruction work
- if atheromatous disease is extensive but distal run-offs is good
- autologous vein grafts superior to prosthetic grafts when knee joint is crossed
What are the causes of acute limb ischameia
- Thrombosis in situ = 40%
- Emboli = 38%
- graft/angioplasty occlusion - 15%
- Trauma
What are the clinical features of acute limb ischaemia
- pale
- pulseless
- pain
- paralysis
- paresthesia
- polar
What is the management of acute limb ischaemia
- Surgical emergency requiring revascularisation within 4-6 hours to save limb
- if diagnosis is in doubt do urgent arteriography
Options
- open surgery or angioplasty
- If embolic: surgical embolectomy, local thrombolysis
- Anticoagulate with heparin after procedure
