Acute + Chronic Limb Ischaemia Flashcards
What is chronic limb ischaemia?
- Peripheral arterial disease, typically of lower limbs causing reduced blood supply
- 5% of males >50yrs have intermittent claudication
What are risk factors for chronic limb ischaemia?
- Smoking
- Diabetes mellitus
- Age
- Hyperlipidaemia
- Family history
- Hypertension
- Obesity
- Physical inactivity
What are the causes of chronic limb ischaemia?
- Atherosclerosis
- Vasculitis (rarely)
What are the clinical features as per the Fontaine classification, for chronic limb ischaemia?
- Stage I → asymptomatic
- Stage II → intermittent claudication
- Stage III → ischaemic rest pain
- Stage IV → ulceration +/- gangrene
The commonest presentation is with pain in the lower limb on exercise (claudication)
What is intermittent claudication?
- cramping/aching pain in buttock or calf
- after walking a fixed distance (claudication distance)
- relieved quickly by rest
What is critical limb ischaemia?
- Unremitting pain at rest (esp at night)
- May be improved by hanging feet out of bed
What is Leriche’s syndrome/triad?
-
Aorto-iliac obstruction
- → Buttock + thigh pain
- → Male impotence
- → Absent femoral pulses
What are signs of chronic limb ischaemia?
- Pulseless
- Pale
- Cool
- Paraesthesia
- Poor wound healing
- Nail dystrophy
- Loss of hair
- Pallor
- Skin changes
What is the ABPI classification in limb ischaemia?
- 1 = normal
- 0.6-0.9 = claudication
- 0.3-0.6 = rest pain
- <0.3 = impending gangrene
Apart from ABPI, what investigations are done for chronic limb ischaemia?
- FBC → anaemia may exacerbate
- ESR → raised in arteritis
- Blood glucose → DM
- Lipids
- ECG → 60% have evidence of coronary artery disease
- Imaging for site, length + degree of stenosis
- Duplex ultrasound (Gold standard)
- Also, CT or MR angiography
How do you interpret doppler USS waveforms for the degree of stenosis?
- Triphasic → normal
- Biphasic → mild stenosis
- Monophasic → severe stenosis
What is the conservative management for chronic limb ischaemia?
- Stop smoking
- Regular exercise
- Weight loss
- Foot care
What is the medical management of chronic limb ischaemia?
- Lipid lowering drugs
- Hypertension control
- Diabetes control
- Antiplatelets (clopidogrel / aspirin)
- Peripheral vasodilator → nafridrofuryl oxalate
- Analgesia
What are the two surgical options for chronic limb ischaemia?
-
Endovascular - angioplasty +/- stent:
- Cross the narrowing or blockage w/ wire, pass balloon over wire, stretch open artery + place stent if needed; less invasive/less risk - better for high risk pts; good for short lesions
-
Open surgical reconstruction:
- Use a conduit (vein or plastic pipe) to go around blockage + restore blood flow distally
- May be anatomical - fem-pop, fem-distal, aorto-bifemoral
- Or extra-anatomical - axillo-femoral, fem-fem crossover
- Ultimately @ 1yr following attempted lower limb bypass operation, 12% of those who initially had critical limb ischaemia + 1% of those with intermittent claudication end up having a major amputation
What is acute limb ischaemia?
- Sudden onset (<2 weeks)
- Painful lack of blood flow to a limb